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You should understand all requirements and restrictions for global-active device operations.

Child Topics

Requirements and restrictions

The following table lists the requirements and restrictions for global-active device operations.

Item

Requirements and restrictions

Primary and secondary storage systems

  • Model:

    The following information is current as of the publish date. See the support matrix at https://support.hitachivantara.com/en_us/interoperability.html to find a complete and current list of support information.

    • VSP G1000 to VSP G1000, VSP G1500 to VSP G1500, VSP F1500 to VSP F1500.

      Note: The same storage systems can be connected. However, only when you upgrade VSP G1000 to VSP G1500, you can temporarily connect a VSP G1000 storage system to a VSP G1500 storage system until you complete the upgrade.

    • VSP G350 to VSP G350, VSP G370 to VSP G370, VSP G700 to VSP G700, VSP G900 to VSP G900
    • VSP F350 to VSP F350, VSP F370 to VSP F370, VSP F700 to VSP F700, VSP F900 to VSP F900

    VSP Gx00 models and VSP Fx00 models can be connected to each other:

    • VSP G350/VSP F350 to VSP G350/VSP F350, VSP G370/VSP F370 to VSP G370/VSP F370, VSP G700/VSP F700 to VSP G700/VSP F700, VSP G900/VSP F900 to VSP G900/VSP F900
  • Microcode:
    • VSP G1000: DKCMAIN 80-01-4x or later
    • VSP G1500: DKCMAIN 80-05-0x or later
    • VSP F1500: DKCMAIN 80-05-0x or later
  • Global-active device license: The global-active device feature must be installed and enabled on the primary and secondary storage systems.
  • Controller emulation type: The controller emulation type of the primary and secondary storage systems must be same.
  • Shared memory:
    • VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900: You can use GAD only with shared memory in the basic part. Adding shared memory expands the capacity of the pairs being created.
    • VSP G1000, VSP G1500, and VSP F1500: Additional shared memory is required in the primary and secondary storage systems.

GAD 3DC delta resync (GAD+UR)

  • The following intermix configurations are supported. No other configurations are supported.
    • VSP G1x00 and VSP F1500 GAD primary storage system, VSP G1x00 and VSP F1500 GAD secondary storage system, VSP G1x00 and VSP F1500 UR storage system.
    • VSP G900 GAD primary storage system, VSP G900 GAD secondary storage system, VSP G900 UR storage system.
    • VSP F900 GAD primary storage system, VSP F900 GAD secondary storage system, VSP F900 UR storage system.
    • VSP G1x00 and VSP F1500 GAD primary storage system, VSP G1x00 and VSP F1500 GAD secondary storage system, VSP G800 or VSP F800 UR storage system.
  • Microcode/firmware:
    • When only VSP G1x00 and VSP F1500 storage systems are used:

      DKCMAIN microcode version 80-02-4x or later

    • When both VSP G1x00 and VSP F1500 and VSP G800 storage systems are used:

      - VSP G1x00 and VSP F1500: DKCMAIN microcode version 80-04-xx-xx/xx or later

      - VSP G800: DKCMAIN firmware version 83-03-XX-XX/XX or later

    • When both VSP G1000, VSP G1500, VSP F1500, and VSP F800 storage systems are used:

      - VSP G1x00 and VSP F1500: DKCMAIN microcode version 80-04-XX or later

      - VSP G800: DKCMAIN firmware version 83-04-2X or later

  • GAD pairs in a GAD+UR configuration must be registered to a consistency group.

External storage systems or servers (for quorum disk)

  • The storage system or server must be supported for attachment using Universal Volume Manager. The server must be attached using iSCSI.

    For details, see the Hitachi Universal Volume Manager User Guide for the storage system.

  • The maximum distance between the external storage system and the primary site and secondary site is 1,500 km.

Licensed capacity

  • The page size assigned to the virtual volume is counted as a licensed capacity for GAD; however, for a volume with capacity saving enabled, the GAD licensed capacity is the capacity before savings.
  • If the actual licensed capacity exceeds the available licensed capacity, GAD can be used as usual for 30 days. After 30 days, only pair split and pair delete operations are allowed.

Host server platforms

  • AIX
  • HP-UX
  • OpenVMS
  • Red Hat Enterprise Linux
  • Solaris
  • SuSE Linux
  • VMware ESX
  • Windows Server
For more information, refer to the Hitachi Vantara interoperability matrix: https://support.hitachivantara.com/en_us/interoperability.html

Maximum number of storage systems that can be connected

One storage system can create pairs with a maximum of 15 storage systems.

SCSI commands

  • The Thin Provisioning function of Windows Server 2012 is supported.
  • The SCSI-2 Reserve command, the SCSI-3 Persistent Reserve command, and the VAAI command are supported.
  • The reservation information is duplicated when the Reserve command or the Persistent Reserve command is received, or when the initial copy or resync copy starts.

Physical paths connecting the primary and secondary storage systems

  • Maximum number of physical paths: 8
  • Maximum distance between the primary and secondary storage systems: 500 km
  • The maximum value of the round-trip delay, including the delay due to the failure of an interface device, is 20 ms. However, you must meet the following conditions to connect storage systems over the distance of 100 km or more.
    • The primary and secondary storage systems are connected by Fibre Channel interfaces.
    • The DKCMAIN microcode version of the primary and secondary storage systems is 80-04-21-00/00 or later for VSP G1000, VSP G1500, VSP F1500.
    • The line speed between the primary and secondary storage systems is 1 Gbps or more.
    • The host mode option 51 is set to ON.
  • Port type: Fibre Channel, iSCSI (VSP G1x00 and VSP F1500 80-03-3x and later) with direct, switch, or channel extenders. For details, see Connection types.
  • Port attribute (VSP G1x00 and VSP F1500): The ports that connect the primary and secondary storage systems must be configured as Initiator ports and RCU target ports.

Remote paths and path groups

  • Maximum number of remote paths per path group: 8
  • Maximum number of path groups per storage system: 64 (sum of the path groups used by TC, UR, and URz)
  • Path group ID: 0-255.
  • Protocol: All remote paths in a path group must be the same protocol, either Fibre Channel or iSCSI. Remote paths for Fibre Channel and iSCSI cannot coexist within the same path group.
  • If iSCSI is used in a remote path, the blocked path monitoring remote replica option must be set to at least 40 seconds (default). If blocked path monitoring is less than 40 seconds, the path might be blocked due to a delay in the network such as many switches in a spanning tree protocol (STP) network or a long distance connection.
  • The path group is specified during the create pair operation and cannot be changed by resynchronization.
  • The remote path must be set by each path group of the storage systems at the primary site and the secondary site.

    You can also use multiple path groups with the same combination of the storage systems at the primary and the secondary sites.

  • When using the System connection type and not the CU connection type (specified on the Add Remote Connection window), specify different paths and path groups for TrueCopy, Universal Replicator, and Universal Replicator for Mainframe secondary storage systems.

Virtual storage machines (VSMs)

  • Maximum number of VSMs per storage system: 8
  • Maximum number of GAD volumes per VSM:
    • VSP G350, VSP F350: 16,384
    • VSP G370, VSP F370: 32,768
    • VSP G700, VSP F700: 49,152
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 65,280
  • You can create GAD pairs using volumes in virtual storage machines. When you want to create a GAD pair using volumes in VSMs, the VSM for the volume in the secondary site must have the same model and serial number as the VSM for the volume in the primary site.
  • (VSP Gx00 models, VSP Fx00 models) When a resource group (virtual storage machine) in a storage system at the secondary site has the same virtual LDEV ID as the P-VOL, you cannot create a GAD pair. In addition, when a volume is not created and only LDEV IDs exist, virtual LDEV IDs must be deleted.
  • The VSP G1x00 and VSP F1500 microcode version for both the primary and secondary storage systems must be 80-02-01 or later to create a GAD pair using a P-VOL that already has a virtual LDEV ID assigned and is managed by a user-defined virtual storage machine. This requirement is not necessary for GAD pairs created by adding secondary storage resources to the primary storage default virtual storage machine.

Resource groups (VSP G1x00 and VSP F1500)

  • DKCMAIN 80-02-xx or later: A volume in a resource group that was migrated from a VSP or USP V/VM storage system to the VSP G1x00 and VSP F1500 can be used as a GAD volume.
  • DKCMAIN 80-01-xx or earlier: A volume in a resource group that was migrated from a VSP or USP V/VM storage system to the VSP G1x00 and VSP F1500 cannot be used as a GAD volume.

Maximum number of GAD pairs

  • When all pairs are created with DP-VOLs and external volumes (calculated by subtracting the number of quorum disks (at least one) from the maximum number of virtual volumes that can be defined in a storage system):
    • VSP G350, VSP F350: 16,382
    • VSP G370, VSP F370: 32,766
    • VSP G700, VSP F700: 49,150
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 63,231
  • When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, and one virtual volume or external volume is used as a command device:
    • VSP G350, VSP F350: 16,381
    • VSP G370, VSP F370: 32,765
    • VSP G700, VSP F700: 49,149
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 63,230
  • When CCI is used in the in-band method and all pairs are created with DP-VOLs or external volumes, and one normal volume (VSP Gx00 models, VSP Fx00 models) or internal volume (VSP G1x00 and VSP F1500) is used as a command device:
    • VSP G350, VSP F350: 16,381
    • VSP G370, VSP F370: 32,765
    • VSP G700, VSP F700: 49,149
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 63,231
  • When all pairs are created with internal volumes (calculated by subtracting the number of quorum disks (at least one) from the maximum number of internal volumes that can be defined in a storage system):
    • VSP G350, VSP F350: 16,383
    • VSP G370, VSP F370: 32,767
    • VSP G700, VSP F700: 49,151
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 65,279
  • When CCI is used in the in-band method and all pairs are created with internal volumes, and one virtual volume or external volume for VSP G1x00 and VSP F1500 is used as a command device:
    • VSP G350, VSP F350: 16,381
    • VSP G370, VSP F370: 32,765
    • VSP G700, VSP F700: 49,149
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 65,277
  • When CCI is used in the in-band method and all pairs are created with internal volumes, and one normal volume (VSP Gx00 models, VSP Fx00 models) or internal volume (VSP G1x00 and VSP F1500) is used as a command device:
    • VSP G350, VSP F350: 16,382
    • VSP G370, VSP F370: 32,766
    • VSP G700, VSP F700: 49,150
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 65,278
  • Virtual storage machine: same as the maximum number of pairs for the storage system model.
  • For details about calculating the maximum number of pairs based on the number of cylinders used in volumes or the number of bitmap areas used in volumes, see Maximum number of GAD pairs.

Pair volumes

  • Provisioning type: The following provisioning types are supported for the GAD pair volumes. The provisioning type of the P-VOL and S-VOL must be same. For example, if the P-VOL is a DP-VOL, the S-VOL must also be a DP-VOL.
    • Dynamic Provisioning virtual volumes (DP-VOLs)

      For DP-VOLs, you can only create a GAD pair when both DP-VOLs do not have the Data Direct Mapping attribute or when both DP-VOLs have the Data Direct Mapping attribute. You cannot create a GAD pair when the Data Direct Mapping attribute is enabled for one DP-VOL but not for the other.

    • Internal volumes
    • External volumes
  • Emulation type: OPEN-V.
  • Volume size: The P-VOL and S-VOL must be equal in size.
  • Maximum volume size:

    DP-VOL: same as the maximum size of a DP-VOL. For details, see the Provisioning Guide for the storage system.

    (VSP G1x00 and VSP F1500)

    • Internal volume: 3,145,663 MB (6,442,317,824 blocks)
    • External volume: 4,194,304 MB (8,589,934,592 blocks)

    (VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900)

    • Internal volume: 256 TB
    • External volume: 256 TB
  • SAN boot: You can use GAD pair volumes for SAN boot.
  • Virtual LDEV ID: The same virtual LDEV ID as the P-VOL must not exist in the resource group of the secondary storage system (virtual storage machine). You cannot create a GAD pair when the same virtual LDEV ID as the P-VOL exists in the resource group of the secondary storage system (virtual storage machine). To use the P-VOL, you must delete the virtual LDEV ID in the resource group of the secondary storage system. You must delete the virtual LDEV ID even if the volume is not created and only the LDEV ID exists.
  • Dynamic volume expansion: You cannot dynamically expand a GAD pair volume. If you need to expand a GAD pair volume, you must delete the pair, expand the volume, and then re-create the pair.
  • T10 PI: The same value must be set for the T10 PI attribute of the P-VOL and the S-VOL.
  • A volume (LDEV) from a parity group with accelerated compression enabled cannot be used directly as a GAD pair volume. Such volumes must be used as pool volumes for an HDP or HDT pool.

Quorum disks

  • Maximum number of quorum disks: 32 per storage system in the primary storage system and secondary storage system.
  • Quorum disk ID: Specify a value from 0 to 31.
  • Maximum number of pairs per quorum disk:
    • VSP G350, VSP F350: 16,382 when you create all pairs with DP-VOLs or external volumes, and 16,383 when you create all pairs with internal volumes.
    • VSP G370, VSP F370: 32,766 when you create all pairs with DP-VOLs or external volumes, and 32,767 when you create all pairs with internal volumes.
    • VSP G700, VSP F700: 49,150 when you create all pairs with DP-VOLs or external volumes, and 49,151 when you create all pairs with internal volumes.
    • VSP G900, VSP F900: 63,232 when you create all pairs with DP-VOLs or external volumes, and 65,279 when you create all pairs with internal volumes.
    • VSP G1x00 and VSP F1500:

      63,231 when you create all pairs with DP-VOLs or external volumes.

      65,279 when you create all pairs with internal volumes.

  • Emulation type (VSP G1x00 and VSP F1500): OPEN-V
  • Minimum size: 12,292 MB (25,174,016 blocks)
  • Maximum size: same as the maximum limit for an external volume supported by Universal Volume Manager: 4 TB.
  • In addition to a volume in an external storage system, a disk in an iSCSI-attached server can be used as a quorum disk if the server is supported by Universal Volume Manager.

    Note: The server and storage systems are connected using iSCSI.

    See Hitachi Universal Volume Manager User Guide for details.

  • One external volume group must be mapped to one external volume.
  • Interoperability: A GAD quorum disk cannot also be used as a High Availability Manager quorum disk for a different storage system model or as a GAD quorum disk for a different storage system model. A GAD quorum disk can be shared only by the same storage system models.
  • Requirements for the external storage system volume:
    • The T10 PI attribute must not be enabled.
    • The Data Direct Mapping attribute must not be set.
    • The volume must not belong to the system resource group.

Consistency groups

  • Maximum number of consistency groups per storage system:
    • VSP G350, VSP G370, VSP G700, VSP F350, VSP F370, VSP F700: 128 (CTG ID 0-127)
    • VSP G1x00 and VSP F1500, VSP G900, VSP F900: 256 (CTG ID 0-255)
  • Maximum number of GAD pairs per consistency group:
    • VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900: 8,192
    • VSP G1x00 and VSP F1500: 8,192

    When different storage system models are connected, the smaller maximum number is applied (for example, the maximum is 128 when VSP G350 and VSP G900 are connected).

  • Quorum disk ID: The same quorum disk ID must be set for all GAD pairs in a single consistency group.
  • VSM: GAD pairs in the same consistency group must be created on the same virtual storage machine.
  • CTG ID: If consistency groups have the same ID but their physical storage systems are different, they are treated as different consistency groups. You can use the same consistency group ID for groups on different storage systems.

Alternate path software

Alternate path software is required for the single-server GAD configuration and the cross-path GAD configuration (two servers). When ALUA is used in the cross-path configuration, use the same models at both the primary and secondary sites.

The following microcode/firmware is required in the storage systems at the primary and secondary sites: DKCMAIN version 80-03-31-00/00 or later for VSP G1x00 and VSP F1500.

Refer to the Hitachi Vantara interoperability matrix: https://support.hitachivantara.com/en_us/interoperability.html

Cluster software

Cluster software is required for the server-cluster and cross-path GAD configurations.

Refer to the Hitachi Vantara interoperability matrix: https://support.hitachivantara.com/en_us/interoperability.html

User interfaces

  • Hitachi Command Suite: 8.0.1 or later

    HCS must be connected to the primary and secondary storage systems.

  • Command Control Interface:
    • VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900: 01-45-03/02 or later
    • VSP G1x00 and VSP F1500: 01-32-03/00 or later

    CCI must be installed on the host connected to the primary and secondary storage systems.

    The CCI command device is required on the primary and secondary storage systems.

Parent Topic

Interoperability requirements

You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Parent Topic
Child Topics

Volume types that can be used for GAD

Knowing the volume types available with other features and whether the volume can be used for GAD operations helps you to operate GAD successful.

Volume type

Used as GAD P-VOL?

Used as GAD S-VOL?

Used as quorum disk?

Dynamic Provisioning / Dynamic Tiering / Active flash

Virtual volume

Yes1

Yes1

No

Pool volume

No

No

No

V-VOL with capacity saving enabled

Yes

Yes

No

Deduplication system data volume

No

No

No

ShadowImage / Thin Image2

P-VOL

Yes

Yes

No

S-VOL

No

No

No

TrueCopy

P-VOL

No

No

No

S-VOL

No

No

No

Universal Replicator

P-VOL

Yes

Yes3

No

S-VOL

No

No

No

Journal volume

No

No

No

Universal Volume Manager

External volume

Yes1

Yes1

Yes

Data Retention Utility

Volume with access attribute

Yes

Yes4

No

Volume Migration

Source volume

No (VSP Gx00 models and VSP Fx00 models)

Yes (VSP G1x00 and VSP F1500)

No (VSP Gx00 models and VSP Fx00 models)

Yes (VSP G1x00 and VSP F1500)

No

Target volume

No

No

No

Cache Residency Manager (VSP G1x00 and VSP F1500)

The volume on which Cache Residency Manager is set

No

No

No

Hitachi Virtual LUN

Virtual LUN volume

Yes

Yes

Yes5

LUN Manager

The volume on which paths are defined

Yes

Yes

No

Volume on which paths are not defined

No

No

Yes

CCI command device

Command device

No

No

No

Remote command device

No

No

No

Encryption License Key

Volume whose parity groups have been encrypted

Yes

Yes

You can use an encrypted volume in the external storage system as a quorum disk.6

Volume which is being migrated

Yes

No

No

Notes:

  1. A DP-VOL that uses an external volume as its pool volume can be used as a GAD P-VOL or S-VOL.
  2. For the node volume or the leaf volume of Thin Image, see the description of the S-VOL, not the P-VOL.
  3. GAD S-VOL is used as UR delta resync pair P-VOL.
  4. If you set the S-VOL Disable attribute of Data Retention Utility to the GAD S-VOL, GAD pair operations using CCI are restricted. Release the S-VOL Disable attribute on the GAD S-VOL, and then perform the GAD pair operations.
  5. Quorum disks can be set only on external volumes that have been configured so that one external volume group is mapped to one external volume.
  6. You cannot encrypt a nonencrypted quorum disk in the external storage system from the primary or secondary storage system.
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Dynamic Provisioning / Dynamic Tiering / Active flash

Dynamic Provisioning, Dynamic Tiering, and active flash virtual volumes (DP-VOLs) can be used as GAD pair volumes.

A V-VOL with capacity saving enabled can be used as a P-VOL or S-VOL of a GAD pair. A deduplication system data volume cannot be used as a P-VOL or S-VOL of a GAD pair.

Note
  • Data compressed or deduplicated by the capacity saving function is copied to a volume after compression and deduplication are released, that is, the capacity saving function is not performed immediately for copied data. Therefore, before creating or resynchronizing a GAD pair, make sure that the available capacity in the copy destination volume is greater than the used capacity in the copy origination volume before capacity saving. For details, see the Provisioning Guide for Open Systems.
  • If you create a GAD pair using a volume for which the capacity saving function is used, compressed or deduplicated data is copied. Because of this, copy or I/O performance might be degraded.
  • When the capacity saving function is used, management information is stored in a pool. As a result, there might be a difference in the number of used pages or licensed capacity between a P-VOL and an S-VOL.
Related References
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

ShadowImage

You can use the GAD P-VOL and S-VOL as a ShadowImage P-VOL.

You can create up to three ShadowImage pairs respectively on the GAD primary and secondary storage systems.

GUID-EA51663B-2A38-45F5-B193-EF3AF172F4B5-low.png

Because the server recognizes a GAD pair as one volume, it sees the volume as paired with six ShadowImage volumes.

GUID-F66AC594-D24E-4B69-8FAD-6FDA4A202C89-low.png

You can create three additional, cascaded SI pairs using the SI S-VOLs. This means that up to nine SI pairs can be created with the GAD P-VOL, and nine SI pairs can be created with the GAD S-VOL.

GUID-DEA8B726-59B5-4DA8-B0B7-CB336179407B-low.png
Note
  • Pairs in an SI consistency group must reside in the same storage system. Because of this, the SI pairs that are associated with both the GAD P-VOL and the S-VOL cannot be registered to the same consistency group.
  • When you use GAD pair volumes to create an SI pair, you must specify the physical LDEV ID, not the virtual LDEV ID.
Related References
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

Limitations when sharing GAD and ShadowImage volumes

Any operation that deletes the virtual LDEV ID of a volume used as a ShadowImage volume cannot be performed.

When a GAD pair is deleted with the P-VOL specified, the virtual LDEV ID of the S-VOL is deleted. If you delete the pair with the S-VOL specified, the virtual LDEV ID of the P-VOL is deleted. When the virtual LDEV ID is deleted, the server does not recognize the volume.

Parent Topic
  • ShadowImage

    You can use the GAD P-VOL and S-VOL as a ShadowImage P-VOL.

SI operations and GAD pair status

The ability to perform a ShadowImage pair operation depends on the SI pair status and GAD pair status.

The following tables show SI pair operations and whether they can be performed (Yes, No) with the listed GAD status. The information assumes the required SI status for the operation.

The Virtual LDEV ID column shows whether the volume has a virtual LDEV ID or not (Yes, No).

Table 1: SI operations when GAD status is Simplex

GAD pair status

Virtual LDEV ID

I/O

ShadowImage pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

SMPL

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

Yes

Yes

No, but the GAD reserve attribute is set

No

No

No

No

No

No

Yes

Table 2: SI operations when GAD status is Mirroring

GAD pair status

I/O mode

Pair location

I/O

ShadowImage pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

INIT/COPY

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No1

Yes

Block

Secondary

No

No

Yes

No2

No2

No1, 3

Yes

COPY

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No1

Yes

Block

Secondary

No

No

Yes

No2

No2

No1, 3

Yes

Notes:

  1. Cannot be used because GAD pairs are not suspended.
  2. Cannot be used because S-VOL data is not fixed.
  3. Cannot be used because the volume at the GAD copy destination is the same as the volume at the ShadowImage copy destination.
Table 3: ShadowImage operations when GAD status is Mirrored

GAD pair status

I/O mode

Pair location

I/O

ShadowImage pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

PAIR

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Secondary

Yes

Yes

Yes

Yes

Yes

No*

Yes

* Cannot be used because GAD pairs are not suspended, and also because the volume at the GAD copy destination is the same as the volume at the ShadowImage copy destination.

Table 4: SI operations when status of GAD pairs created, resynchronized, or swap resynchronized is Quorum disk blocked

GAD pair status

I/O mode

Pair location

I/O

ShadowImage pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

Microcode version 80-04-2x or earlier (VSP G1x00 and VSP F1500)

PAIR

Mirror(RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Block

Secondary

No

No

Yes

Yes

Yes

No*

Yes

Microcode version 80-05-0x or later (VSP G1x00 and VSP F1500), firmware version 88-01-0x or later (VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

PAIR

Mirror(RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Mirror(RL)

Secondary

Yes

Yes

Yes

Yes

Yes

No*

Yes

* Cannot be used because GAD pairs are not suspended, and also because the volume at the GAD copy destination is the same as the volume at the ShadowImage copy destination.

Table 5: ShadowImage operations when GAD status is Suspended

GAD pair status

I/O mode

Pair location

I/O

ShadowImage pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

PSUS

Local

Primary

Yes

Yes

Yes

Yes

Yes

Yes*

Yes

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

PSUE

Local

Primary

Yes

Yes

Yes

Yes

Yes

Yes*

Yes

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

Secondary

No

No

Yes

Yes

Yes

No

Yes

SSUS

Block

Secondary

No

No

Yes

Yes

Yes

No

Yes

SSWS

Local

Secondary

Yes

Yes

Yes

Yes

Yes

Yes*

Yes

* Quick Restore cannot be executed. For VSP G1x00 and VSP F1500, if the microcode is 80-05-7x or later, Quick Restore can be executed.

Table 6: ShadowImage operations when GAD status is Blocked

GAD pair status

I/O mode

Pair location

I/O

SI pair operations

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

PSUE

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

Secondary

No

No

Yes

Yes

Yes

No

Yes

Parent Topic
  • ShadowImage

    You can use the GAD P-VOL and S-VOL as a ShadowImage P-VOL.

GAD operations and SI pair status

The ability to perform a GAD pair operation depends on GAD pair status and SI pair status.

The following tables show GAD operations and whether they can be performed (Yes, No) with the listed SI status. The information assumes the required GAD status for the operation.

Table 1: GAD operations and SI pair statuses, when GAD P-VOL is shared

SI pair status

GAD pair operations

Create pairs

Suspend pairs

Delete pairs

Resync pairs

P-VOL selected

S-VOL selected

P-VOL selected1

S-VOL selected2

Forced deletion

P-VOL selected

S-VOL selected

SMPL(PD)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PAIR

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY(SP)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PSUS(SP)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PSUS

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY(RS)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY(RS-R)

No4

impossible

impossible

Yes

No3

Yes

No4

No4

PSUE

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the P-VOL, only when the I/O mode is Local and the GAD pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the S-VOL, only when the I/O mode is Local and the GAD pair status of the S-VOL is SSWS.
  3. Cannot be used because, when you delete a GAD pair specifying the S-VOL, the P-VOL's virtual LDEV ID is also deleted, which makes it unusable as the SI P-VOL.
  4. To continue SI restore copy, the GAD pairs must be suspended.
Table 2: GAD operations and SI pair statuses, when GAD S-VOL is shared

SI pair status

GAD pair operations

Create pairs

Suspend pairs

Delete pairs

Resync pairs

P-VOL selected

S-VOL selected

P-VOL selected1

S-VOL selected2

Forced deletion

P-VOL selected

S-VOL selected

SMPL(PD)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PAIR

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY(SP)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PSUS(SP)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PSUS

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY(RS)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY(RS-R)

No3, 5

impossible

impossible

No4

Yes

Yes

No5, 6

No6

PSUE

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the P-VOL, only when the I/O mode is Local and the GAD pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the S-VOL, only when the I/O mode is Local and the GAD pair status of the S-VOL is SSWS.
  3. When a GAD pair is created, the GAD reserve attribute is assigned to the volume that will become the S-VOL, which removes the virtual LDEV ID of this volume, making it unusable as an SI pair volume.

    The GAD reserve attribute is set, and the virtual LDEV ID is deleted for the volume that will become the GAD S-VOL, making it unusable as an SI volume.

  4. Cannot be used because, when you delete a GAD pair specifying the S-VOL, the P-VOL's virtual LDEV ID is also deleted, which makes it unusable as the SI P-VOL.
  5. Cannot be used because the volume at the GAD copy destination is the same as the volume at the ShadowImage copy destination.
  6. To continue ShadowImage restore copy, GAD pairs must be suspended.
Related References
  • ShadowImage

    You can use the GAD P-VOL and S-VOL as a ShadowImage P-VOL.

Parent Topic
  • ShadowImage

    You can use the GAD P-VOL and S-VOL as a ShadowImage P-VOL.

Thin Image

You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

You can create up to 1,024 Thin Image pairs using a GAD P-VOL, and up to 1,024 Thin Image pairs using a GAD S-VOL.

GUID-079A63FB-8947-4EDA-B22B-FD2374637B48-low.png

Because the server recognizes the GAD pair as one volume, it sees the volume as paired with 2,048 HTI volumes.

GUID-A4745568-7E7D-4F43-9106-C4CEFF72721C-low.png
Note
  • Pairs in an HTI consistency group and snapshot group must reside in the same storage system. Because of this, the HTI pairs that are associated with both the GAD P-VOL and S-VOL cannot be registered to the same consistency group or snapshot group.
  • When you use GAD pair volumes to create a Thin Image pair, specify the physical LDEV ID, not the virtual LDEV ID.
Related References
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

Limitations for using both GAD and Thin Image

Any operation that deletes the virtual LDEV ID of a volume used as a Thin Image volume cannot be performed.

When a GAD pair is deleted with the P-VOL specified, the virtual S-VOL's LDEV ID is deleted. If you delete the pair with the S-VOL specified, the P-VOL's virtual LDEV ID is deleted. When the virtual LDEV ID is deleted, the server does not recognize the volume, making it unusable as a Thin Image volume.

Parent Topic
  • Thin Image

    You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

Thin Image operations and GAD status

The ability to perform a Thin Image pair operation depends on the HTI pair status and the GAD pair status.

The following tables show HTI operations and whether they can be performed (Yes, No) with the listed GAD status. The information assumes the required HTI status for the operation.

The Virtual LDEV ID column shows whether the volume has a virtual LDEV ID or not (Yes, No).

Table 1: Thin Image operations when GAD status is Simplex

GAD pair status

Virtual LDEV ID

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs

SMPL

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

Yes

Yes

Yes

Yes

Yes

No, but the GAD reserve attribute is set

No

No

No

No

No

No

Yes

Table 2: Thin Image operations when GAD status is Mirroring

GAD pair status

I/O mode

Pair location

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs

INIT/COPY

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No1

Yes

Block

Secondary

No

No

No

No2

No2

No1, 3

Yes

COPY

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No1

Yes

Block

Secondary

No

No

No

No2

No2

No1, 3

Yes

Notes:

  1. Cannot be used because GAD pairs are not suspended.
  2. Cannot be used because the data is being copied and the volume data is not fixed yet.
  3. Cannot be used because the volume at the GAD copy destination is the same as the volume at the Thin Image copy destination.
Table 3: Thin Image operations when GAD status is Mirrored

GAD pair status

I/O mode

Pair location

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs

PAIR

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Secondary

Yes

Yes

Yes

Yes

Yes

No*

Yes

* Cannot be used because GAD pairs are not suspended, and also because the volume at the GAD copy destination is the same as the volume at the Thin Image copy destination.

Table 4: Thin Image operations when status of GAD pairs created, resynchronized, or swap resynchronized is Quorum disk blocked

GAD pair status

I/O mode

Pair location

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs/Suspend copy

Microcode version 80-04-2x or earlier (VSP G1x00 and VSP F1500)

PAIR

Mirror (RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Block

Secondary

No

No

Yes

Yes

Yes

No*

Yes

Microcode version 80-05-0x or later (VSP G1x00 and VSP F1500), firmware version 88-01-0x or later (VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

PAIR

Mirror(RL)

Primary

Yes

Yes

Yes

Yes

Yes

No*

Yes

Mirror(RL)

Secondary

Yes

Yes

Yes

Yes

Yes

No*

Yes

* Cannot be used because GAD pairs are not suspended, and also because the volume at the GAD copy destination is the same as the volume at the Thin Image copy destination.

Table 5: Thin Image operations when GAD status is Suspended

GAD pair status

I/O mode

Pair location

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs

PSUS

Local

Primary

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

PSUE

Local

Primary

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

Secondary

No

No

Yes

Yes

Yes

No

Yes

SSUS

Block

Secondary

No

No

Yes

Yes

Yes

No

Yes

SSWS

Local

Secondary

Yes

Yes

Yes

Yes

Yes

No

Yes

Table 6: Thin Image operations when GAD status is Blocked

GAD pair status

I/O mode

Pair location

I/O

Thin Image pair operation

Read

Write

Create pairs

Split pairs

Resync pairs

Restore pairs

Delete pairs

PSUE

Block

Primary

No

No

Yes

Yes

Yes

No

Yes

Secondary

No

No

Yes

Yes

Yes

No

Yes

Related References
  • Thin Image

    You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

Parent Topic
  • Thin Image

    You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

GAD operations and Thin Image pair status

The ability to perform a GAD pair operation depends on the GAD pair status and the HTI pair status.

The following tables show GAD operations and whether they can be performed (Yes, No) with the listed HTI status. The information assumes the required GAD status for the operation.

Table 1: GAD operations and HTI pair status, when the GAD P-VOL is shared

TI pair status

GAD pair operations

Create GAD Pairs

Suspend Pairs

Delete Pairs

Resync Pairs

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Forced deletion

P-VOL specified

S-VOL specified

SMPL(PD)

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PAIR

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

PSUS

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

COPY(RS-R)

No4

impossible

impossible

Yes

No3

Yes

No4

No4

PSUE

Yes

Yes

Yes

Yes

No3

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the P-VOL, only when the I/O mode is Local and the GAD pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the S-VOL, only when the I/O mode is Local and the GAD pair status of the S-VOL is SSWS.
  3. Cannot be used because, when you delete a GAD pair specifying the S-VOL, the P-VOL's virtual LDEV ID is also deleted, which makes it unusable as the HTI P-VOL.
  4. To continue resynchronizing the HTI pair, you must split the GAD pair.
Table 2: GAD operations and HTI pair status, when the GAD S-VOL is shared

TI pair status

GAD pair operations

Create GAD Pairs

Suspend Pairs

Delete Pairs

Resync Pairs

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Forced deletion

P-VOL specified

S-VOL specified

SMPL(PD)

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PAIR

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

PSUS

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

COPY(RS-R)

No3, 5

No

No

No4

Yes

Yes

No5, 6

No6

PSUE

No3

Yes

Yes

No4

Yes

Yes

Yes

Yes

Notes:

  1. You can delete a GAD pair by specifying the primary volume, only when the I/O mode is Local and the GAD pair status of the primary volume is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the secondary volume, only when the I/O mode is Local and the GAD pair status of the secondary volume is SSWS.
  3. To create a GAD pair, you must assign the GAD reserve attribute to the volume used as an S-VOL. Because the virtual LDEV ID of the volume to which the GAD reserve attribute is assigned is deleted, you cannot create a GAD pair by specifying the volume shared with HTI as the S-VOL of the pair.
  4. Cannot be used because, when you delete a GAD PAIR specifying the P-VOL, the S-VOL's virtual LDEV ID is also deleted, which makes it unusable as an HTI P-VOL.
  5. Cannot be used because the GAD pair's target volume is the same as the HTI pair's target volume.
  6. To continue resynchronizing the HTI pair, you must split the GAD pair.
Related References
  • Thin Image

    You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

Parent Topic
  • Thin Image

    You can use a GAD P-VOL or S-VOL as a Thin Image (HTI) P-VOL.

Use cases for pairing GAD volumes with SI or HTI

Backing up GAD pair volumes with ShadowImage (SI) or Thin Image (HTI) provides further protection for GAD data.

Further protection for GAD data is provided in the following ways:

  • When the GAD pair is resynchronized, pair status changes to COPY. While in this status, S-VOL consistency is temporarily lost. You can protect data when in COPY status by pairing the S-VOL with SI or HTI before resynchronizing the GAD pair.
  • Though data in a blocked GAD pair is inconsistent, host activity can continue with the P-VOL or S-VOL. Therefore, before correcting the failure by forcibly deleting the pair, you should pair the volumes with SI or HTI.
  • The SI and HTI pairs can then be copied, and the copies used for other purposes.
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Universal Replicator

You can combine GAD and Universal Replicator to create a configuration that can continue to operate in the event of a multi-site failure.

In a GAD system, the server accesses the primary and secondary sites simultaneously and shares the same data between the two sites (at campus distance). If a failure occurs at one site, you can continue operations at the other site. However, if a failure occurs at both sites, for example due to a large-scale disaster, you will not be able to continue operations with the data redundancy provided only by GAD.

To manage this situation, you can implement a 3-data-center (3DC) configuration by combining GAD and Universal Replicator (UR). This configuration is called a GAD 3DC delta resync (GAD+UR) configuration. If there is a failure at both the primary site and the GAD secondary site, the GAD+UR configuration enables you to continue operations using the UR secondary site (at metro distance).

Note
  • When all storage systems in a GAD+UR configuration are VSP G1x00 and VSP F1500, the DKCMAIN microcode version must be 80-02-4-xx/xx or later. If both VSP G1000, VSP G1500, VSP F1500 and VSP G800 or VSP F800 exist, the DKCMAIN firmware version for VSP G1x00 and VSP F1500 must be 80-04-xx-xx/xx or later; and for VSP G800, the DKCMAIN firmware version must be 83-03-xx-xx/xx or later, or for VSP F800, the DKCMAIN firmware version must be 83-04-2x-xx/xx or later. You cannot combine GAD and UR using other storage system models.
  • If both VSP F800 and VSP G1000, VSP G1500, VSP F1500 exist, the DKCMAIN microcode version for VSP G1000, VSP G1500, and VSP F1500 must be 80-04-xx-xx/xx or later, and for VSP F800, the DKCMAIN firmware version must be 83-04-2x-xx/xx or later.
  • The CCI remote command device is not required in GAD+UR configurations.
  • Volumes in a 3DC GAD+UR configuration cannot be shared with the following volumes:
    • UR volumes in a system with multiple storage systems in the primary and secondary sites
    • UR volumes in a 3DC multi-target configuration with TC and UR
    • UR volumes in a 3DC multi-target configuration with 3 UR sites
    • UR volumes in a 3DC cascade configuration with 3 UR sites
  • 3DC multi-target configuration and 3DC cascade configuration with GAD and UR are supported only by VSP G900, VSP F900, VSP G1x00 and VSP F1500.

The following figure shows the required configuration for GAD+UR operations. You must use this configuration when combining GAD with UR.

GUID-70408026-B1C4-484B-88D9-7769CC2663EF-low.png

In a GAD+UR configuration:

  • The P-VOL of the GAD pair functions as the P-VOL of the UR pair.
  • The S-VOL of the GAD pair functions as the P-VOL of the UR delta resync pair.
  • The UR S-VOL has two mirror IDs, one for the UR pair, and one for the UR delta resync pair.
  • The UR delta resync pair consists of the GAD S-VOL at the GAD secondary site and the UR S-VOL at the UR secondary site. This UR delta resync pair allows you to synchronize the UR pair S-VOL by using the journal data at the GAD secondary site in the event of a failure at the primary site.
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

GAD pair and Universal Replicator pair interoperability

You should know how GAD pairs and Universal Replicator pairs work together for different pair statuses for GAD pairs or UR pairs.

The following table shows GAD pair operations and whether they can be performed (Yes or No) with the listed UR pair status.

Table 1: GAD operations and UR pair statuses
UR pair status Attribute of the target UR pair GAD pair operation
Create pairs1 Split pairs Suspend pairs Resynchronize pairs Delete pairs
P-VOL specified S-VOL specified P-VOL specified S-VOL specified P-VOL or S-VOL specified

COPY

P-VOL

No

Yes

impossible

Yes

Yes

No2

S-VOL

No

No3

impossible

No

impossible

No2

PAIR

P-VOL

No

Yes

impossible

Yes

Yes

No2

S-VOL

No

No3

impossible

No

impossible

No2

PSUS

P-VOL

No

Yes

impossible

Yes

Yes

No2

PSUE

P-VOL

No

Yes

impossible

Yes

Yes

No2

S-VOL

No

No3

impossible

No

impossible

No2

SSUS

S-VOL

No

No3

impossible

No

impossible

No2

SSWS

S-VOL

No

No3

impossible

No

impossible

No2

HOLD

P-VOL

No

impossible

Yes

impossible

impossible

No2

S-VOL

No

impossible

impossible

impossible

impossible

No2

HLDE

P-VOL

No

impossible

Yes

impossible

impossible

No2

S-VOL

No

impossible

impossible

impossible

impossible

No2

Note:
  1. When creating a GAD and UR configuration, create a GAD pair first.
  2. When deleting a GAD pair, delete the UR pair and the UR delta resync pair first.

  3. The UR S-VOL is also used as the GAD P-VOL only when the UR S-VOL is duplicated using GAD. In this case, the GAD P-VOL status must be PSUS, therefore, the pair split terminates abnormally.

The following table shows UR pair operations and whether they can be performed (Yes or No) with the listed GAD pair status.

Table 2: UR pair operations and GAD pair statuses
GAD pair status I/O mode Attribute of the target GAD pair UR pair operation
Create pairs Split pairs Suspend pairs Resynchronize pairs
P-VOL specified S-VOL specified P-VOL specified S-VOL specified

INIT/COPY

Mirror (RL)

P-VOL

No

Yes

impossible

Yes1

impossible

Block

S-VOL

No

impossible

impossible

impossible

impossible

COPY

Mirror (RL)

P-VOL

No

Yes

impossible

Yes1

impossible

Block

S-VOL

No

impossible

impossible

impossible

impossible

PAIR

Mirror (RL)

P-VOL

Yes2

Yes

impossible

Yes1

impossible

S-VOL

No

impossible

impossible

impossible

impossible

PSUS

Local

P-VOL

No

Yes

Yes3

Yes1

Yes3

Block

P-VOL

No

Yes

Yes3

No

impossible

PSUE

Local

P-VOL

No

Yes

Yes3

Yes1

Yes3

Block

P-VOL

No

Yes

Yes3

No

impossible

SSUS

Block

S-VOL

No

impossible

impossible

impossible

impossible

SSWS

Local

S-VOL

No

Yes

impossible

Yes

impossible

Note:

  1. Can be performed only when the UR delta resync pair status is HLDE.

  2. GAD pairs can be used with UR pairs only when the volume specified as the UR S-VOL is a UR delta resync S-VOL.
  3. The UR S-VOL is also used as the GAD P-VOL only when the UR S-VOL is duplicated using GAD.

The following table shows UR delta resync pair operations and whether they can be performed (Yes or No) with the listed GAD pair status.

Table 3: UR delta resync pair operations and GAD pair statuses
GAD pair status I/O mode Attribute of the target GAD pair UR delta resync pair operation
Create UR delta resync pair Delta resync Delete pairs
P-VOL specified S-VOL specified UR delta resync P-VOL UR delta resync S-VOL

INIT/COPY

Mirror (RL)

P-VOL

No

No1

Yes

impossible

impossible

impossible

Block

S-VOL

No

No1

impossible

impossible

impossible

impossible

COPY

Mirror (RL)

P-VOL

No

No1

Yes

impossible

impossible

impossible

Block

S-VOL

No

No1

impossible

impossible

impossible

impossible

PAIR

Mirror (RL)

P-VOL

No

No1

Yes

impossible

impossible

impossible

S-VOL

Yes

No1

impossible

impossible

Yes4

impossible

PSUS

Local

P-VOL

No

No1

Yes

Yes3

Yes4

impossible

Block

P-VOL

Yes2

No1

Yes

Yes3

Yes4

impossible

PSUE

Local

P-VOL

No

No1

Yes

Yes3

Yes4

impossible

Block

P-VOL

Yes2

No1

Yes

Yes3

Yes4

impossible

SSUS

Block

S-VOL

No

No1

impossible

impossible

Yes4

impossible

SSWS

Local

S-VOL

No

No1

Yes

impossible

Yes4

impossible

Note:

  1. Cannot be performed by users. The storage system performs the operation automatically.
  2. If a failure occurs at the primary site, the operation can be performed only when the volume specified as the UR delta resync S-VOL is the UR S-VOL.
  3. The UR S-VOL is also used as the GAD P-VOL only when the UR S-VOL is duplicated using GAD.
  4. Deleting a UR delta resync pair deletes the UR pair.
Parent Topic
  • Universal Replicator

    You can combine GAD and Universal Replicator to create a configuration that can continue to operate in the event of a multi-site failure.

Data Retention Utility

You can create a GAD pair using volumes that have been assigned the Data Retention Utility access attribute.

  • When you create or resynchronize a GAD pair, the access attribute set for the P-VOL is copied to the S-VOL.
  • If you change the access attribute when GAD status is Mirrored or Mirroring, make sure to set the access attribute to both the P-VOL and S-VOLs.
  • Server I/O can be controlled, depending on GAD status and the access attribute.
  • If you set the Data Retention Utility S-VOL Disable attribute on the GAD S-VOL, GAD pair operations using CCI are restricted. Release the S-VOL Disable attribute from the S-VOL, then perform CCI operations.
Related References
Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

GAD status and I/O allowance by access attribute

Even when the access attribute is assigned to a GAD volume, the initial copy and pair resynchronization operations are not controlled. The following table shows whether server I/O is allowed for the listed GAD status and access attribute.

GAD statuses

Access attribute

I/O

P-VOL

S-VOL

P-VOL

S-VOL

Mirrored

Read/Write

Read/Write

Ends normally

Ends normally

Read Only or Protect

Read/Write

Depends on the attribute*

Ends normally

Read/Write

Read Only or Protect

Ends normally

Depends on the attribute*

Read Only or Protect

Read Only or Protect

Depends on the attribute*

Depends on the attribute*

Quorum disk blocked (status of GAD pairs created, resychronized, or swap resynchronized on 80-04-2x or earlier for VSP G1x00 and VSP F1500)

Read/Write

Read/Write

Ends normally

Rejected

Read Only or Protect

Read/Write

Depends on the attribute*

Rejected

Read/Write

Read Only or Protect

Ends normally

Rejected

Read Only or Protect

Read Only or Protect

Depends on the attribute*

Rejected

Quorum disk blocked (status of GAD pairs created, resychronized, or swap resynchronized on 80-05-0x or later for VSP G1x00 and VSP F150088-01-0x or later for VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

Read/Write

Read/Write

Ends normally

Ends normally

Read Only or Protect

Read/Write

Depends on the attribute*

Ends normally

Read/Write

Read Only or Protect

Ends normally

Depends on the attribute*

Read Only or Protect

Read Only or Protect

Depends on the attribute*

Depends on the attribute*

Mirroring

Suspended (when the I/O mode of the primary volume is Local and the I/O mode of the secondary volume is Block)

Read/Write

Read/Write

Ends normally

Rejected

Read Only or Protect

Read/Write

Depends on the attribute*

Rejected

Read/Write

Read Only or Protect

Ends normally

Rejected

Read Only or Protect

Read Only or Protect

Depends on the attribute*

Rejected

Suspended (when the I/O mode of the primary volume is Block and the I/O mode of the secondary volume is Local)

Read/Write

Read/Write

Rejected

Ends normally

Read Only or Protect

Read/Write

Rejected

Ends normally

Read/Write

Read Only or Protect

Rejected

Depends on the attribute*

Read Only or Protect

Read Only or Protect

Rejected

Depends on the attribute*

Block

Read/Write

Read/Write

Rejected

Rejected

Read Only or Protect

Read/Write

Rejected

Rejected

Read/Write

Read Only or Protect

Rejected

Rejected

Read Only or Protect

Read Only or Protect

Rejected

Rejected

* If the attribute is Read Only, Read is allowed but not Write. If the attribute is Protect, Read and Write are not allowed.

Related References
  • Data Retention Utility

    You can create a GAD pair using volumes that have been assigned the Data Retention Utility access attribute.

Parent Topic
  • Data Retention Utility

    You can create a GAD pair using volumes that have been assigned the Data Retention Utility access attribute.

Volume Migration (VSP G1x00 and VSP F1500)

You can use Volume Migration to move volumes in an overloaded drive to a non-overloaded drive online.

Volume Migration moves volumes by specifying the P-VOL and S-VOL of a GAD pair in an overloaded drive as the migration source volume which then moves the volumes to a non-overloaded drive.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

Restrictions for using GAD with Volume Migration

There are restrictions of which you should be aware before you use Volume Migration to move a GAD pair volume.

  • The GAD pair must be split before you specify the volumes as the migration source volumes for Volume Migration.
  • Provisioning types of the GAD P-VOL and S-VOL must be the same. Ensure that the provisioning types of the GAD P-VOL and S-VOL are still the same after the migration by Volume Migration.
  • When a GAD pair volume is shared by an SI pair volume, you cannot specify it as the source volume during Quick Restore of the SI pair. When Quick Restore completes, start using Volume Migration.
  • For Volume Migration operation when using GAD with nondisruptive migration, see GAD status and nondisruptive migration pair operations.
Parent Topic

GAD status and Volume Migration pair operations

The ability of Volume Migration to create or cancel migration plans depends on the status of the GAD pair.

The following table describes if you can create or cancel migration plans when GAD volumes are not mirrored.

GAD pair status

Virtual LDEV ID

I/O from the server

Volume Migration operation

Read

Write

Create migration plans

Cancel migration plans

SMPL

Available

Y

Y

Y

Y

Not available

N

N

N

Y

Not available (Virtual attribute: GAD reserve)

N

N

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table describes if you can create or cancel migration plans when GAD volumes are being mirrored.

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Create migration plans

Cancel migration plans

INIT/COPY

Mirror(RL)

Primary

Y

Y

N

Y

Block

Secondary

N

N

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table describes if you can create or cancel migration plans when GAD volumes are mirrored.

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Create migration plans

Cancel migration plans

PAIR

Mirror(RL)

Primary

Y

Y

N

Y

Secondary

Y

Y

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table describes if you can create or cancel migration plans when the GAD pair is suspended.

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Create migration plans

Cancel migration plans

PSUS/PSUE

Local

Primary

Y

Y

Y

Y

Block

Any

N

N

Y

Y

SSUS

Block

Secondary

N

N

Y

Y

SSWS

Local

Secondary

Y

Y

Y

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table describes if you can create or cancel migration plans when the GAD pair is blocked.

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Create migration plans

Cancel migration plans

PSUE

Block

Primary

N

N

Y

Y

Secondary

N

N

Y

Y

Legend

Y: Can be performed

N: Cannot be performed

Parent Topic

Volume Migration pair statuses and GAD pair operations (VSP G1x00 and VSP F1500)

You should understand what GAD operations you can perform given the Volume Migration pair status and whether the GAD P-VOL or S-VOL is shared by Volume Migration.

The following table describes operations you can perform according to the Volume Migration pair status when the GAD P-VOL is shared by Volume Migration.

Volume Migration pair status

GAD pair operation

Create

Suspend

Delete

Resynchronize

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Force delete

P-VOL specified

S-VOL specified

SMPL(PD)

No4

Yes

Yes

Yes

No3

Yes

No

No

COPY

No4

Yes

Yes

Yes

No3

Yes

No

No

PSUS

No4

Yes

Yes

Yes

No3

Yes

No

No

PSUE

No4

Yes

Yes

Yes

No3

Yes

No

No

Note:
  1. You can delete a GAD pair by specifying the P-VOL, only when the I/O mode is Local and the GAD pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the S-VOL, only when the I/O mode is Local and the GAD pair status of the S-VOL is SSWS.
  3. Cannot be performed because the virtual LDEV ID of the GAD P-VOL (volume for Volume Migration) is deleted if you specify the S-VOL to delete the GAD pair.
  4. To perform Volume Migration, you must suspend the GAD pair.

The following table describes operations you can perform according to the Volume Migration pair status when the GAD S-VOL is shared by Volume Migration.

Volume Migration pair status

GAD pair operation

Create

Suspend

Delete

Resynchronize

P-VOL specified

S-VOL specified

P-VOL specified1

S-VOL specified2

Force delete

P-VOL specified

S-VOL specified

SMPL(PD)

No3

Yes

Yes

No4

Yes

Yes

No

No

COPY

No3

Yes

Yes

No4

Yes

Yes

No

No

PSUS

No3

Yes

Yes

No4

Yes

Yes

No

No

PSUE

No3

Yes

Yes

No4

Yes

Yes

No

No

Note:
  1. You can delete a GAD pair by specifying the primary volume, only when the I/O mode is Local and the GAD pair status of the primary volume is PSUS or PSUE.
  2. You can delete a GAD pair by specifying the secondary volume, only when the I/O mode is Local and the GAD pair status of the secondary volume is SSWS.
  3. To create a GAD pair, you must assign the GAD reserve attribute to the volume used as an S-VOL. Because the virtual LDEV ID of the volume to which the GAD reserve attribute is assigned is deleted, you cannot create a GAD pair by specifying the volume used for Volume Migration as the S-VOL of the pair.
  4. Cannot be performed because the virtual LDEV ID of the GAD S-VOL (volume for Volume Migration) is deleted if you specify the P-VOL to delete the GAD pair.
Parent Topic

LUN Manager

Use the volumes for which LU paths have been set to create a GAD pair. You can add LU paths to or delete LU paths from GAD pair volumes. However, you cannot delete the last LU path because at least one LU path must be set for GAD pair volumes.

A volume for which no LU path has been set cannot be used as a GAD pair volume.

CautionWhen you remove the path that is defined on an LDEV with the GAD reserve attribute, the path removal might fail if the number of LDEVs whose path is to be removed is too large.

When a port has a path defined for an LDEV with the GAD reserve attribute and you need to configure the port (delete a host group, set a command device, or change the host mode, topology, AL-PL, or transfer speed), the operation might fail if you configure more than one port at a time. For ports that have a path defined on an LDEV with the GAD reserve attribute, perform these operations on one port at a time.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Virtual Partition Manager

GAD pair volumes and quorum disks can migrate CLPRs.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Nondisruptive migration (VSP F1500 and VSP G1x00)

You can create a GAD pair using a volume being migrated by nondisruptive migration to migrate your data without changing system configuration, even if your system is designed for disaster recovery. The following figure shows an example of such data migration. For example, If you create a GAD pair using a volume being migrated while maintaining the configuration of the disaster recovery system using TrueCopy, you can maintain the disaster recovery system by GAD soon after migration.

GUID-2AA845FC-F144-4DB3-96A7-CC650B2ABE35-low.png

For details, see the Nondisruptive Migration User Guide.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

Restrictions for using GAD with nondisruptive migration

You should be aware of restrictions if you want to use GAD with nondisruptive migration.

  • When creating a GAD pair, you cannot specify a volume being migrated by nondisruptive migration as its S-VOL.
  • Before creating a GAD pair, you need to change the cache mode of the destination volume to Write Sync. Use CCI when changing the cache mode.
  • I/O operations from the host to the GAD S-VOL cannot be performed until Volume Migration is completed. If you want to perform the operation which allows the host to recognize the GAD S-VOL, perform this operation after Volume Migration is completed.
  • You cannot swap resynchronize GAD pairs. If you want to swap resynchronize them, delete Volume Migration pairs after Volume Migration ends.
  • Before you start Volume Migration, set the same provisioning type for both the target volume of Volume Migration and the GAD S-VOL.
  • 3-data-center (3DC) configurations using both GAD and Universal Replicator (UR) cannot be used for destination volumes. To use a 3DC configuration combining GAD and UR, configure the 3DC system after volumes are completely migrated by Volume Migration.
Parent Topic

GAD status and nondisruptive migration pair operations

The following table shows the cache modes of nondisruptive migration and GAD pair operations.

Operation target

Virtual LDEV ID

GAD pair operation

P-VOL

S-VOL

Cache modes for external volume groups of the destination storage system

TM (Cache Through)

N

N

SM (Write Sync)

Y

N

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of GAD pair operation and cache mode change in nondisruptive migration.

Operation target

Cache modes to which GAD P-VOL can be changed

TM (Cache Through)

SM

EM/DM

GAD P-VOL

N

Y

N

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of Volume Migration pair operations (when a GAD pair operating with nondisruptive migration is in the initial status).

GAD pair status

Virtual LDEV ID

I/O from the server

Volume Migration operation

Read

Write

Migrate volumes

Stop migrating volumes

SMPL

Specifed

Y

Y

Y

Y

None

N

N

N

Y

None (GAD reserve is specified as the virtual attribute)

N

N

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of Volume Migration pair operations (when a GAD pair operating with nondisruptive migration is being mirrored).

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Migrate volumes

Stop migrating volumes

INIT/COPY

Mirror (RL)

P-VOL

Y

Y

N

Y

Block

S-VOL

N

N

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of Volume Migration pair operations (when a GAD pair operating with nondisruptive migration is already mirrored).

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Migrate volumes

Stop migrating volumes

PAIR

Mirror (RL)

P-VOL

Y

Y

Y

Y

Block

S-VOL

N

N

N

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of Volume Migration pair operations (when a GAD pair operating with nondisruptive migration is suspended).

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Migrate volumes

Stop migrating volumes

PSUS/PSUE

Local

P-VOL

Y

Y

Y

Y

Block

Volume of your own choice (P-VOL or S-VOL)

N

N

Y

Y

SSUS

Block

S-VOL

N

N

Y

Y

SSWS

Local

S-VOL

Y

Y

Y

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the possibility of Volume Migration pair operations (when a GAD pair operating with nondisruptive migration is blocked).

GAD pair status

I/O mode

Pair location

I/O from the server

Volume Migration operation

Read

Write

Migrate volumes

Stop migrating volumes

PSUE

Block

P-VOL

N

N

Y

Y

S-VOL

N

N

Y

Y

Legend

Y: Can be performed

N: Cannot be performed

The following table shows the GAD pair status in Volume Migration when GAD and nondisruptive migration are used together, and the possibility of Volume Migration pair operations (when the GAD P-VOL is a target volume of Volume Migration).

Volume Migration pair status

Is VM P-VOL shared with NDM?

Is VM S-VOL shared with NDM?

GAD pair operation

Create

Suspend

Delete

Resynchronize

P-VOL specified

S-VOL specified

P-VOL specified 1

S-VOL specified 2

Force delete

P-VOL specified 3

S-VOL specified

SMPL (PD)

Yes

No4

Y

Y

Y

Y

N

Y

N

N

COPY

Yes

No4

N

Y

Y

Y

N

Y

N

N

PSUE

Yes

No4

N

Y

Y

Y

N

Y

N

N

PSUS

No4

Yes

N

Y

Y

Y

N

Y

N

N

Legend

VM: Volume Migration

NDM: nondisruptive migration

Y: Can be performed

N: Cannot be performed

Note:

  1. You can delete a GAD pair by specifying its P-VOL, only when the I/O mode is Local and the pair status of the P-VOL is PSUS or PSUE.
  2. You can delete a GAD pair by specifying its S-VOL, only when the I/O mode is Local and the pair status of the S-VOL is SSWS.
  3. If a GAD pair is suspended due to a failure, you can resynchronize it by deleting the Volume Migration pair, and then specifying the GAD P-VOL.
  4. You cannot use the S-VOL of Volume Migration as a volume of nondisruptive migration.
Parent Topic

Volume Shredder

GAD pair volumes and quorum disks cannot use Volume Shredder to delete data.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Performance Monitor

Performance Monitor can be used to collect performance information about GAD pair volumes and the quorum disk.

The amount of a port's I/O that can be added to Performance Monitor depends on the type of the volume to which I/O is issued, or on the volume's I/O mode.

For example, when the I/O mode of both GAD volumes is Mirror (RL), each time the server writes to the P-VOL, performance data is recorded for all of the following ports and volumes:

  • Primary storage system port connected to the host (Target)
  • Primary storage system port connected to the secondary storage system (Initiator)
  • Secondary storage system port connected to the primary storage system (RCU Target)
  • P-VOL
  • S-VOL

When the I/O mode of both GAD volumes is Mirror (RL), each time the server reads the P-VOL data, performance data is recorded for only the primary storage system host (Target) port and the P-VOL.

Parent Topic
  • Interoperability requirements

    You should understand how global-active device (GAD) operates with other features of the VSP G1000, VSP G1500, VSP F1500, VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900 storage systems.

Child Topics

Server I/Os added to Performance Monitor

The number of I/Os (reads and writes) to GAD volumes that is added to Performance Monitor depends on the GAD status, as shown the following tables.

Table 1: Writes to GAD volumes to be added to Performance Monitor

GAD status

P-VOL

S-VOL

Mirrored

The sum of the following values:

  • Number of writes to the P-VOL
  • Number of RIOs to the P-VOL from the S-VOL

The sum of the following values:

  • Number of reads from the S-VOL
  • Number of RIOs to the S-VOL from the P-VOL

Quorum disk blocked (status of GAD pairs created, resynchronized, or swap resynchronized on 80-04-2x or earlier for VSP G1x00 and VSP F1500 88-01-0x or later for VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

Number of writes to the P-VOL

Number of RIOs to the S-VOL from the P-VOL

Quorum disk blocked (status of GAD pairs created, resynchronized, or swap resynchronized on 80-05-0x or later for VSP G1x00 and VSP F150088-01-0x or later for VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

Number of writes to the P-VOL

The sum of the following values:

  • Number of writes from the server to the S-VOL
  • Number of RIOs from the P-VOL to the S-VOL

Mirroring

Number of writes to the P-VOL

Number of RIOs to the S-VOL from the P-VOL

Suspended (when the P-VOL has the latest information)

Number of writes to the P-VOL

Not counted*

Suspended (when the S-VOL has the latest information)

Not counted*

Number of writes to the S-VOL

Blocked

Not counted*

Not counted*

* Reads and writes by a server are illegal requests and cause an error. However, they could be counted as I/O.

Table 2: Reads to GAD volumes to be added to Performance Monitor

GAD status

P-VOL

S-VOL

Mirrored

Number of reads from the P-VOL

Number of reads from the S-VOL

Quorum disk blocked (status of GAD pairs created, resynchronized, or swap resynchronized on 80-04-2x or earlier for VSP G1x00 and VSP F1500 )

Number of reads from the P-VOL

Not counted*

Quorum disk blocked(status of GAD pairs created, resynchronized, or swap resynchronized on 80-05-0x or later for VSP G1x00 and VSP F150088-01-0x or later for VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

Number of reads from the P-VOL

Number of reads from the S-VOL

Mirroring

Number of reads from the P-VOL

Not counted*

Suspended (when the P-VOL has the latest information)

Number of reads from the P-VOL

Not counted*

Suspended (when the S-VOL has the latest information)

Not counted*

Number of reads from the S-VOL

Blocked

Not counted*

Not counted*

* Reads and writes from a server are illegal requests and cause an error. However, they could be counted as I/O.

Table 3: Relation between amount of I/O added to Performance Monitor and amount of server I/O

GAD status

Number of writes

Number of reads

Mirrored

Approximately the same* as the number of writes to the P-VOL or S-VOL

The same as the total number of reads from the P-VOL and S-VOL

Quorum disk blocked (status of GAD pairs created, resynchronized, or swap resynchronized on 80-04-2x or earlier for VSP G1x00 and VSP F1500 )

The same as the number of writes to the P-VOL

The same as the number of reads from the P-VOL

Quorum disk blocked (status of GAD pairs created, resynchronized, or swap resynchronized on 80-05-0x or later for VSP G1000, VSP G1500, VSP F1500, 88-01-0x or later for VSP G350, G370, G700, G900 and VSP F350, F370, F700, F900)

The same as the number of writes to the P-VOL

The same as the total number of reads from the P-VOL and S-VOL

Mirroring

The same as the number of writes to the P-VOL

The same as the number of reads from the P-VOL

Suspended (P-VOL has latest data)

The same as the number of writes to the P-VOL

The same as the number of reads from the P-VOL

Suspended (S-VOL has latest data)

The same as the number of writes to the S-VOL

The same as the number of reads from the S-VOL

Blocked

Not counted

Not counted

* For writes by a server, RIOs might be divided before being issued. For this reason, this number might differ from the number of writes by a server.

Parent Topic
  • Performance Monitor

    Performance Monitor can be used to collect performance information about GAD pair volumes and the quorum disk.

Port I/Os added to Performance Monitor

The number of I/Os (reads or writes) of the port added to Performance Monitor depends on the P-VOL or S-VOL (I/O destination), or on the I/O mode of the destination volume, as shown in the following table.

I/O destination volume I/O mode

I/O destination volume

Primary storage system

Secondary storage system

Target

Initiator

RCU Target

Target

Initiator

RCU Target

Mirror (RL)

P-VOL

Total writes and reads

Number of writes

Not added

Not added

Not added

Number of writes

S-VOL

Not added

Not added

Number of writes

Total writes and reads

Number of writes

Not added

Local

P-VOL

Total writes and reads

Not added

Not added

Not added

Not added

Not added

S-VOL

Not added

Not added

Not added

Total writes and reads

Not added

Not added

Block

P-VOL

Total writes and reads*

Not added

Not added

Not added

Not added

Not added

S-VOL

Not added

Not added

Not added

Total writes and reads*

Not added

Not added

* Reads and writes by a server are illegal requests and cause an error. However, they might be counted as I/Os.

Related References
  • Performance Monitor

    Performance Monitor can be used to collect performance information about GAD pair volumes and the quorum disk.

Parent Topic
  • Performance Monitor

    Performance Monitor can be used to collect performance information about GAD pair volumes and the quorum disk.