Requirements and specifications

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You need to understand the system and interoperability requirements to successfully use Hitachi Universal Replicator.

System requirements

The following table lists the system requirements for UR operations.

Item	Requirement
Supported storage systems (VSP 5100 and VSP 5500)	VSP 5100 and VSP 5500 can be paired with the following: VSP 5100 and VSP 5500 (90-01-00-00/00 or later) VSP G1000 (80-06-70-00/00 or later) VSP G1500, and VSP F1500 (80-06-70-00/00 or later) VSP (70-06-63-00/00 or later) VSP E990 (93-02-01 or later) VSP E590, VSP E790 (93-03-22 or later) In addition, VSP 5100 and VSP 5500 with DKCMAIN microcode version 90-08-01-xx/xx or later can be connected to: VSP 5200 and VSP 5600: all microcode versions VSP 5100 and VSP 5500 with DKCMAIN microcode version 90-08-22-00/00 or later can be connected to: VSP E1090: 93-06-22-x0/00 or later VSP G350, G370, G700, G900, and VSP F350, F370, F700, F900: 88-03-26-xx/xx or later
Supported storage systems (VSP 5200 and VSP 5600)	VSP 5200 and VSP 5600 can be paired with the following: VSP 5000 series: 90-08-01-xx/xx or later VSP G1000, VSP G1500, and VSP F1500: 80-06-87-xx/xx or later VSP E590, VSP E790, VSP E990: 93-05-93-xx/xx or later In addition, VSP 5200 and VSP 5600 with DKCMAIN microcode version 90-08-22-00/00 or later can be connected to: VSP E1090: 93-06-22-x0/00 or later In addition, VSP 5200 and VSP 5600 with DKCMAIN microcode version 90-08-61-xx/xx or later can be connected to: VSP G700, VSP F700, VSP G/F900 (88-08-08-xx/xx or later)
Supported storage systems (VSP E590 or VSP E790)	VSP E590, VSP E790 can be connected to: VSP E590, VSP E790, VSP E990: 93-03-22-x0/00 or later VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900: 88-07-01-x0/00 or later VSP G200, G400, G600, G800, VSP F400, F600, F800: 83-05-38-x0/00 or later VSP 5100 and VSP 5500: 90-05-01-00/00 or later In addition, VSP E590 and VSP E790 with microcode version 93-05-03-xx/xx or later can be connected to: VSP 5200 and VSP 5600: all microcode versions VSP E1090: all microcode versions
Supported storage systems (VSP E990)	VSP E990 can be connected to: VSP E590, VSP E790, VSP E990: All models VSP G350, VSP G370, VSP G700, VSP G900, VSP F350, VSP F370, VSP F700, VSP F900: 88-04-02-xx/00 or later VSP G200, G400, G600, G800, VSP F400, F600, F800: 83-05-36-xx/00 or later VSP 5100 and VSP 5500: 90-02-01-00/00 or later In addition, VSP E990 with microcode version 93-05-03-xx/xx or later can be connected to: VSP 5200 and VSP 5600: all microcode versions VSP E1090: all microcode versions
Supported storage systems (VSP E1090)	VSP E1090 can be connected to: VSP E series: 93-06-01-00/00 or later VSP 5000 series: 90-08-02-00/00 or later VSP G700, VSP F700, VSP G/F900 (88-08-08-xx/xx or later)
Number of storage systems (VSP 5000 series)	A maximum of 64 units can be connected to one unit storage system. For example, you can make a configuration of one unit storage system for the primary site and 64 units storage system for the secondary site. When you create a 3DC cascade configuration with TC, at least one unit of the storage system is required for each of the primary site, intermediate site, or secondary site. When you create a 3DC multi-target delta resync configuration with TC, at least one unit of the storage system is required for each site. When you create a 3DC cascade multi-target delta resync configuration with three UR sites, at least one unit of the storage system is required for each site. For information about VSP 5000 series URxUR support, contact customer support
Number of storage systems (VSP E series)	The maximum number of storage systems that can be connected to one unit storage system depends on the models. A maximum of 64 units can be connected to one unit storage system. For example, you can make a configuration of one unit storage system for the primary site and 64 units storage system for the secondary site. When you create a 3DC cascade configuration with TC, at least one unit of the storage system is required for each of the primary site, intermediate site, or secondary site. When you create a 3DC multi-target delta resync configuration with TC, at least one unit of the storage system is required for each site. When you create a 3DC cascade multi-target delta resync configuration with three UR sites, at least one unit of the storage system is required for each site.
Universal Replicator	Must be installed on the primary and secondary storage systems. License keys required. UR and URz can coexist in the same storage system. The pair with the available licensed capacity exceeded cannot be created. For licensing capacity requirements when UR volumes are shared with other software products, see Dynamic Provisioning . For information on expired licenses or exceeding licensed capacity, see the System Administrator Guide.
Other licenses required	TrueCopy is required, whether or not TC volumes are shared with UR. Remote Replication Extended is required for 3DC configurations. Dynamic Provisioning. DP-VOLs are required for journal volumes.
Interfaces	Device Manager - Storage Navigator: Must be LAN-attached to the primary storage system. Not required on the secondary storage system, but recommended in order to change UR parameters and access the S-VOL for disaster recovery and maintenance. The following roles are required: Storage Administrator (Remote Copy), to perform pair operations Storage Administrator (System Resource Management), to configure settings CCI: Command device required (VSP 5000 series) When using virtual storage machine volumes, specify the LDEV ID, serial number, and virtual information in the configuration definition file.
Supported host platforms (when Fibre Channel or iSCSI is used for connection between the host and storage system)	AIX HP-UX OpenVMS Red Hat Enterprise Linux Solaris SuSE Linux VMWare ESX Windows Server For the supported version, refer to the Hitachi Vantara interoperability matrix at https://compatibility.hitachivantara.com.
Supported host platforms (when NVMe-oF is used for connection between the host and storage system)	A UR pair that uses a volume connected to a host using NVMe-oF is supported by the following storage systems: VSP 5000 series with the DKCMAIN microcode version 90-08-21-XX or later VSP E1090 with the DKCMAIN microcode version 93-06-61-XX or later For details about the supported host platforms, contact customer support.
Data path	The following interfaces with direct, switch, or channel extenders are available: Fibre channel iSCSI For details, see Supported data path configurations . Note that a data path of the NVMe-oF interface is not supported. Up to eight paths can be registered in one path group. You can use multiple path groups by registering path groups with multiple path group IDs in the same storage system, but note that only one path group can be specified for a mirror.
Path group	Groups of remote paths, which allows you to configure or change the configuration of multiple paths at the same time. A maximum of eight remote paths can be registered in a path group. A maximum of 64 path groups can be set in a storage system. The range of values for the path group ID is 0-255. Two path group IDs can be set in a port. 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. For a mirror, the path group ID that is used to connect the primary storage system to the secondary storage system must also be used to connect the systems in the reverse direction. The path group is specified during the create pair operation. It cannot be changed by resynchronization or the swap operation. Path groups can be created and specified using BCM or CCI. See configuration setting commands in Command Control Interface User and Reference Guide and sample configuration definition files in Command Control Interface Installation and Configuration Guide. Specify different paths and path groups for TC and UR secondary storage systems when using CU Free.
Pair volumes	The P-VOL and S-VOL must be equal in size. The P-VOL and S-VOL must be the same emulation type. Supported emulation type: OPEN-V (VSP 5000 series) The maximum capacity of the P-VOL and S-VOL is 256 TB. (VSP 5000 series) The minimum volume size of the P-VOL and S-VOL is 46.875 MB (96,000 blocks). ( VSP E series) The maximum and minimum capacity of the P-VOL and S-VOL is: Internal and external volume: Same as the maximum and minimum capacity of the CVs. DP-VOL: Same as the maximum and minimum capacity of the DP-VOL. For details, see the Provisioning Guide for your storage system. You need to set the same value for T10 PI attribute for both P-VOL and S-VOL. The LUN paths must be defined for both P-VOL and S-VOL, or both P-VOL and S-VOL must be defined as namespaces on the NVM subsystems to which NVM subsystem ports have been added. A volume (LDEV) from a parity group with accelerated compression enabled cannot be used directly as a pair volume. Such volumes must be used as pool volumes for an HDP or HDT pool. The following storage systems support Universal Replicator configurations that use, as pair volumes, the volumes (namespaces) connected to hosts using the NVMe-oF interface: VSP E1090 (DKCMAIN microcode version: 93-06-61-XX/XX or later) VSP 5000 series (DKCMAIN microcode version: 90-08-21-XX/XX or later) However, VSP E1090 supports such Universal Replicator configurations only when both the primary and secondary sites consist only of VSP E1090 storage systems.
Journals and journal volumes (VSP 5000 series)	Maximum number of journals supported per storage system: 256 (0 to 255) Preferred number of journals: up to 4 for each MP unit Maximum number of journal volumes: 2. Note: The second journal volume becomes the reserve journal volume and is not used for normal operations. Maximum number of data volumes: 16,384 for each journal, and 8,192 for each mirror. When you create a 3DC multi-target or 3DC cascade configuration with three UR sites, use the same data volume in two mirrors. Maximum journal volume size: 256 TB Minimum journal volume size: 10 GB Maximum number of data volumes per journal: 8,192 Emulation types for journal volumes: OPEN-V. Journal volumes must be DP-VOLs. The following volumes cannot be registered to a journal: A DP-VOL with the Data Direct Mapping attribute. A DP-VOL with the capacity saving enabled. A deduplication system data volume. The relationship between a master journal and a restore journal is called a mirror. Mirror IDs are 0 to 3. Journal IDs cannot be duplicated among the virtual storage machines. For details, see Planning journal volumes .
LU number, namespace ID	LU number: 0 to 4095. The number of LU paths that can be created can be up to 4096 for VSP 5000 series whose DKCMAIN program version is 90-02-0x-xx/xx or later. The number of LU paths that can be created when connecting a VSP 5000 series with an earlier DKCMAIN program version is limited to 2048. The number of LU paths that can be created when connecting a different source storage system is limited to 2048. For details about an LU number, see Restrictions when creating an LU whose LU number is 2048 or greater. For details about a namespace ID and LU number, see the Provisioning Guide for Open Systems.
Journals and journal volumes (VSP E series)	Maximum number of journals: VSP E590, VSP E790: 128 (journal ID: 0 to 255) 256 journal IDs are available, but you can use only 128 of those IDs. VSP E990, VSP E1090: 256 (journal ID: 0 to 255) Preferred number of journals: VSP E590: up to 4 for each MP unit (up to 8 for the whole storage system) VSP E790: up to 8 for each MP unit (up to 16 for the whole storage system) VSP E990, VSP E1090: up to 16 for each MP unit (up to 32 for the whole storage system) Maximum number of data volumes in a journal: VSP E series: 8,192 per journal Maximum number of journal volumes in a journal is two. The second journal is used as the reserve (spare) journal volume. Only Dynamic Provisioning virtual volumes (DP-VOLs) can be used as journal volumes. The following volumes cannot be registered to a journal: A DP-VOL with the Data Direct Mapping attribute. A DP-VOL with the capacity saving enabled. A deduplication system data volume. Virtual storage machine volumes cannot be used as journal volumes. Data volumes belonging to different virtual storage machines cannot be registered to the same journal. Maximum journal volume size: 256 TB Minimum journal volume size: 1.5 GB Journal volume capacity is not included in Universal Replicator capacity cost. Journal IDs cannot be duplicated among the virtual storage machines.
Supported volume types	Virtual LUN: Can be used for data and journal volumes. S-VOL capacity must equal P-VOL capacity. Cache Residency Manager: Data volume: yes Journal volume: no
Maximum number of pairs	VSP 5000 series: 65,280 pairs (maximum) VSP E590: 32,768 pairs (maximum), 16,384 pairs or fewer (recommended) VSP E790: 49,152 pairs (maximum), 24,576 pairs or fewer (recommended) VSP E990, VSP E1090: 65,280 pairs (maximum), 32,640 pairs or fewer (recommended) VSP G350, VSP F350: 16,384 pairs (maximum), 8,192 pairs or fewer (recommended) VSP G370, VSP F370: 32,768 pairs (maximum), 16,384 pairs or fewer (recommended) VSP G700, VSP F700: 49,152 pairs (maximum), 24,576 pairs or fewer (recommended) VSP G900, VSP F900: 65,280 pairs (maximum), 32,640 pairs or fewer (recommended)
Number of consistency groups	Requirement: VSP E590, VSP E790: Up to 128 CTGs (0 to 127) VSP E990, VSP E1090: Up to 256 CTGs (0 to 255) VSP G350, VSP G370, VSP G700, VSP F350, VSP F370, VSP F700: Up to 128 CTGs (0 to 127) VSP G900, VSP F900: Up to 256 CTGs (0 to 255)
Supported RAID groups	RAID1, RAID5, and RAID6 are supported for both data and journal volumes. RAID1, RAID5, and RAID6 can co-exist in the same journal.
Cache and nonvolatile storage (NVS)	Must be operable for primary and secondary storage systems to ensure pair creation success. The secondary storage system cache must be configured to adequately support UR remote-copy workloads, as well as local workload activity. To determine the appropriate cache capacity to be increased, perform the following calculations A and B and use the smaller result: A. 1 GB × number of journals B. 25% of the necessary cache to support the storage capacity Note: When pair status is COPY, neither cache nor shared memory can be added to or removed from the system. When either of these tasks is to be performed, first split any pairs in COPY status, and then resynchronize when the cache or shared memory operation is completed.
Host failover software	Required for disaster recovery.
CCI consistency groups with multiple primary and secondary storage systems	In the CCI CTG with multiple storage systems, a maximum of four units storage system can be connected. For example, you can configure the CCI CTG storage system of four units each for the primary site and secondary site. Likewise, you can configure the CCI CTG multiple systems of two units storage system for the primary site and one unit storage system for the secondary site. VSP 5000 series: Up to 8,192 pairs. You can register the total number of pairs in the journals within one CCI consistency group. It is recommended that you register only up to 4,096 pairs. VSP G900, VSP F900, VSP E series: Up to 65,280 pairs. It is recommended that you register only up to 32,640 pairs. VSP G700, VSP F700: Up to 49,152 pairs. It is recommended that you register only up to 24,576 pairs. VSP G370, VSP F370: Up to 32,768 pairs. It is recommended that you register only up to 16,384 pairs. VSP G350, VSP F350: Up to 16,384 pairs. It is recommended that you register only up to 8,192 pairs.

Interoperability requirements

This topic provides the interoperability requirements for Universal Replicator.

Universal Replicator can be used extensively with TrueCopy and ShadowImage to provide additional data redundancy and enhanced disaster recovery solutions. For information about these configurations, see the following appendixes:

Volume types that can be shared with Universal Replicator

You can use volumes used by other software products as UR P-VOLs, S-VOLs, and journal volumes. The following table shows whether a particular software product volume can be used as a UR P-VOL, S-VOL, or journal volume.

Volumes types and functions	Used as UR P-VOL?	Used as UR S-VOL?	Used as UR journal volume?
Cache Residency Manager (VSP 5000 series)
Volume set for CRM	Yes	Yes	No
Cross-OS File Exchange (VSP 5000 series)
Volume usable by both mainframe and open systems	No	No	No
Data Retention Utility
Volume with Read/Write attribute	Yes	Yes	Yes
Volume with Protect attribute	Yes	Yes	No
Volume with Read Only attribute	Yes	Yes	No
Volume that is disabled for use as an S-VOL	Yes	Only when resyncing a UR pair.	No
Dynamic Provisioning ⁶
Virtual volume	Yes	Yes	Yes
Virtual volume with Data Direct Mapping attribute	Yes	Yes	No
Pool volume with Data Direct Mapping attribute	No	No	No
Pool-VOL	No	No	No
V-VOL with capacity saving enabled	Yes	Yes	No
Deduplication system data volume	No	No	No
Dynamic Tiering / Active flash
Virtual volume	Yes	Yes	No
Pool-VOL	No	No	No
Global-active device¹³
P-VOL	Yes¹⁹	No	No
S-VOL	Yes^{9, 19}	No	No
Quorum disk	No	No	No
Volume with reserve attribute for S-VOL	No	No	No
Global storage virtualization
Volumes in a virtual storage machine	Yes⁵^{, 19}	Yes⁵	No
LUN Manager
Volume to which an LU path is defined	Yes	Yes	No
Volume defined as a namespace for NVMe	Yes²⁰	Yes²⁰	No
Volume that is protected by namespace security for NVMe-oF	Yes²⁰	Yes²⁰	No
Volume to which no LU path is defined or a volume that is not defined as a namespace for NVMe	No	No	Yes
Volume to which LUN security is applied	Yes	Yes	No
Resource Partition Manager
Resource Partition Manager volume	Yes¹⁷	Yes¹⁷	Yes¹⁸
ShadowImage⁷
P-VOL in PSUS status	Yes	Yes ^{12, 16}	No
P-VOL in PSUE status	Yes	Yes ^{12, 16}	No
P-VOL in COPY(RS-R)/RCPY status	No	No	No
P-VOL that is also used as a TC P-VOL or S-VOL	Yes	Yes ^{12, 16}	No
P-VOL (None of the above)	Yes	Yes ^{6, 12, 16}	No
S-VOL in PSUS status	Yes	No	No
S-VOL in PSUE status	Yes	No	No
S-VOL (None of the above)	No	No	No
Thin Image^10,¹⁴
P-VOL in all statuses except RCPY	Yes¹	Yes^{2, 10, 11}	No
P-VOL in RCPY status	No	No	No
V-VOL	No	No	No
pool-VOL	No	No	No
Thin Image Advanced(VSP 5000 series)^10,¹⁴
P-VOL in all statuses except RCPY	Yes	Yes	No
P-VOL in RCPY status	No	No	No
S-VOL	No	No	No
TrueCopy ^{8, 15}
P-VOL in COPY status	No	No	No
P-VOL in PAIR status	Yes¹⁹	No	No
P-VOL in PSUS status	Yes¹⁹	No³	No
P-VOL in PSUE status	Yes¹⁹	No³	No
S-VOL in COPY status	No	No	No
S-VOL in PAIR status	Yes¹⁹	No	No
S-VOL in PSUS status	Yes¹⁹	No	No
S-VOL in SSWS status	Yes¹⁹	No³	No
S-VOL in PSUE status	Yes¹⁹	No	No
Universal Volume Manager
Universal Volume Manager volume	Yes	Yes	No
Virtual LUN
Virtual LUN volume	Yes	Yes	No
Volume Migration¹⁵
Source volume (when volume migration is in progress)	Yes⁴	Yes⁴	No
Source volume (after volume migration is finished)	Yes	Yes	No
Notes: The volume can be used as a UR pair volume for delta resync. The UR pair must be created first, otherwise No. The volume can be used as an S-VOL only when you resync a UR pair or perform the horctakeover operation, though even in these cases, it cannot be used in a pair for a delta resync operation. UR pair status must be other than COPY or PAIR to use the P-VOL or the S-VOL as a source volume and perform volume migration. The migration operation stops if UR pair status changes to COPY or PAIR. A volume whose virtual LDEV ID is deleted cannot be used as a UR pair volume. When a DP-VOL is used as a pair volume shared by ShadowImage and UR, the UR create pair operation can fail. For information about how to ensure against failure, see the bullet on DP-VOL s and ShadowImage in Dynamic Provisioning . For complete information, see Configurations with ShadowImage. For complete information, see Configurations with TrueCopy. The volume must be used as the P-VOL of a UR delta resync pair. You cannot specify a volume used as a Thin Image P-VOL as an S-VOL when creating a UR pair. You can specify a Thin Image P-VOL as an S-VOL when creating a UR delta resync pair in a 3DC multi target or 3DC cascade configuration with three UR sites. If you want to use DP-VOLs that are also used by a ShadowImage pair or used by a Volume Migration migration plan, perform the following operations: Delete the ShadowImage pair and disable the Volume Migration setting first. Create a UR pair. Re-create a ShadowImage pair and a Volume Migration migration plan. For more information on using Universal Replicator with global-active device, see the Global-Active Device User Guide. For the node volume or the leaf volume of Thin Image, see the description of the V-VOL, not the P-VOL. For the node volume and the leaf volume of Thin Image Advanced, see the description of the S-VOL, not the P-VOL. In a 3DC multi-target or 3DC cascade configuration in which three UR sites are combined, the volume shared with the two UR pairs cannot be used by this software. Also, the volume used in this software cannot be used as the volume shared with the two UR pairs. For 3DC configurations with three UR sites, do not assign the P-VOL of an SI pair that uses DP-VOLs of Dynamic Provisioning as the S-VOL of a UR pair for delta resync. Only volumes assigned to user group to which the user belongs can be used. Only OPEN-V virtual volumes assigned to user group to which the user belongs can be used. The following configurations are not supported for a volume connected to a host by using NVMe-oF: 3DC cascade, 3DC multi-target, and 3DC delta resync configurations with UR and TC 3DC cascade, 3DC multi-target, and 3DC delta resync configurations with three UR sites 3DC delta resync configuration with GAD and UR Volumes that are set as NVMe namespaces can be used for Universal Replicator pair volumes with the following DKCMAIN microcode versions: VSP 5000 series: DKCMAIN version 90-08-21-xx or later VSP E series: DKCMAIN microcode version 93-06-61-XX-XX/XX or later

Using DP-VOLs that are also used by ShadowImage pairs or Volume Migration

You can use DP-VOLs that are also used by a ShadowImage pair or that is used in a Volume Migration migration plan, but the UR pair must be created first.

If the ShadowImage pair or the Volume Migration setting is enabled before you create the UR pair, you must delete or disable them before creating the UR pair.

Procedure

Delete the ShadowImage pair or disable the Volume Migration setting.
Create the UR pair.
Re-create the ShadowImage pair or the Volume Migration migration plan.

Cache Residency Manager

CRM volumes can be used as Universal Replicator P-VOLs and S-VOLs.

You can perform CRM operations on a Universal Replicator pair’s P-VOL and S-VOL.
CRM volumes cannot be used as journal volumes.

Data Retention Utility

You can create a Universal Replicator pair using volumes that have been assigned the access attribute by the Data Retention Utility. However, you cannot specify a volume with the "S-VOL Disable" attribute as a Universal Replicator S-VOL.

The following table shows whether the access attribute can be changed or referenced.

UR pair status and DRU operations
UR volume	UR pair status	DRU access attribute changed?	DRU access attribute referenced?
P-VOL	Unpaired	Yes	Yes
	COPY	See next table.	Yes
	PAIR	See next table.	Yes
	PSUS	Yes	Yes
	PSUE	Yes	Yes
S-VOL	Unpaired	Yes	Yes
	COPY	No	Yes
	PAIR	No	Yes
	PSUS	No	Yes
	PSUE	No	Yes

The following table shows when changes can be made to the access attribute when the Universal Replicator P-VOL status is PAIR or COPY.

Whether access attribute can be changed when UR P-VOL status is PAIR or COPY
Change access attribute from	Change access attribute to
Change access attribute from	Read/Write	Read Only	Protect	S-VOL Disable
Read/Write	-	No	No	Yes
Read Only	Yes	-	Yes	Yes
Protect	Yes	Yes	-	Yes
S-VOL Disable.	Yes	No	No	-

Dynamic Provisioning

You can create a Universal Replicator pair by specifying a DP-VOL (Dynamic Provisioning virtual volume).

DP-VOLs can be used for either the UR P-VOL or S-VOL, or both P-VOL and S-VOL.
A DP-VOL with the capacity saving enabled can be used as a P-VOL or S-VOL of a UR pair. The deduplication system data volume cannot be used as a P-VOL or S-VOL of a UR pair, or as a journal volume.

When the UR pair using a DP-VOL with capacity saving disabled is in COPY status, the P-VOL capacity saving can be enabled. Capacity savings of a UR pair P-VOL does not begin until after the pair status changes to something other than COPY.
DP-VOLs cannot be used as journal volumes.
When a DP-VOL is used for a UR P-VOL or S-VOL, the UR of the allocated pages for the DP-VOL is included in the UR licensed capacity. If the actual licensed capacity exceeds the available licensed capacity, the pair creation cannot be performed, regardless of whether a normal volume or a DP-VOL is used. In addition, 30 days after the licensed capacity is exceeded, UR pairs may only be split or released, regardless of whether a normal volume or a DP-VOL is used.
The UR licensed capacity for a volume with capacity saving enabled is the capacity before savings.
When you specify a DP-VOL that has allocated pages to a UR S-VOL, the used pool capacity will become temporarily larger than the actual capacity, because pages must be reallocated in the DP-VOL. Therefore, before creating the pair:
- Make sure that DP-VOL pool capacity is sufficient.
- Make sure that the pool-VOLs, which are added to a pool, are not blocked. If the pool-VOLs are blocked, restore the volume status and then create the pair.
If you want to use DP-VOLs that are also used by a ShadowImage pair or that are in a Volume Migration migration plan, proceed as follows:
1. Delete the ShadowImage pair or disable the Volume Migration setting.
2. Create the UR pair.
3. Re-create the ShadowImage pair or the Volume Migration migration plan.
When a DP-VOL is used as the UR S-VOL, you might not be able to update the UR S-VOL because the capacity of the pool-VOL is full. In this instance:
- The pair is suspended.
- With CCI, the UR pair status changes to PFUS.
- In Device Manager - Storage Navigator, the UR pair status changes to PSUS.
When both of the following conditions exist, pages that do not exist in the P-VOL might be assigned to the S-VOL when splitting and then resynchronizing the pair:
- The copy pace is Faster.
- The pair is created and the pair status is COPY.
To delete S-VOL pages that do not exist in the P-VOL, use the Reclaim Zero Pages function for the DP-VOL.
(Virtual Storage Platform 5000 series) Data compressed or deduplicated by the capacity saving function is copied to a volume after compression and deduplication are released. The capacity saving function is not performed immediately for copied data. Before creating or resynchronizing a UR 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.
If you create a UR pair using a volume for which the capacity saving function is used, compressed or deduplicated data is copied. Copy or I/O performance might be degraded because of this.
When installing Universal Replicator, if you enable the capacity saving function of the S-VOL to create a UR pair, specify Slower or Medium for Copy Pace in HDvM - SN, or execute the raidcom modify journal command of CCI by specifying a value between 1 to 3 for the -copy_size option. If you specify Faster, and perform an initial copy, the processing for the capacity saving function conflicts with restoration. As a result, the copy pace becomes slower than Faster.

If you want to specify Faster, disable the capacity saving function first, and then enable it again after the copy processing completes.
When the capacity saving function is used, management information is stored in a pool. As a result, there might be differences between a P-VOL and an S-VOL in the number of used pages or licensed capacity.
You can expand the capacity of DP-VOLs used as UR pair volumes if the microcode version for both the primary and secondary storage systems is the following version:
- VSP 5000 series: 90-04-04-00/00 or later
- VSP G/F350, G/F370, G/F700, G/F900: 88-06-02-x0/00 or later
- VSP E series: 93-02-03-x0/00 or later
For more information about the procedure for expanding the DP-VOL capacity, see Expansion of DP-VOL capacity while keeping pair status.

Preparing a virtual volume for use as an S-VOL

You need to prepare a virtual volume for use as the S-VOL of a UR pair if that virtual volume has capacity saving enabled and has assigned pages.

Procedure

Perform LDEV formatting on the volume you want to use as the S-VOL.
If you create a pair without performing LDEV formatting, the initialization is performed during the copy operation, which might increase the required time for copying or might raise the processor operating rate.
Set the capacity saving mode that you want to use on the S-VOL to the mode that satisfies your user requirements.
- Set the post-process mode if the user requirement is to suppress the impact on the I/O performance.
  Using this mode, the S-VOL requires the pool capacity to be as large as the P-VOL because capacity saving is performed after the pair is created.
- Set the inline mode if the user requirement is to suppress the required pool capacity.
  The required time for copying might be longer or the processor operating rate might be greater than that in the post-process mode. Consider applying the post-process mode to suppress the required time or processor operating rate.
  If you use any of the following DKCMAIN firmware versions and create a pair without performing LDEV formatting, the post-process mode is applied even if you set the inline mode. Therefore, ensure that the pool capacity is as large as the P-VOL.
  - VSP 5000 series: Earlier than 90-05-04-xx/xx
  - VSP 5000 series: 90-06-01-xx.xx or later, earlier than 90-06-21-xx/xx
  - VSP E series: Earlier than 93-04-02-xx/xx

Global-active device

In a GAD system, the server accesses the primary site and GAD secondary site simultaneously and shares the same data between the two sites (at campus distance). If a failure occurs at one of the sites, 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 three-data-center (3DC) configuration by combining GAD and Universal Replicator. This configuration is called a 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).

The following figure shows a GAD+UR configuration. Always use this configuration for GAD+UR operations.

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 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.

A special case for using the GAD+UR configuration is to migrate the UR environment between the current primary and secondary sites to different primary and secondary sites while keeping the UR pairs. You can also migrate the GAD+UR environment to different sites using GAD. For details about the GAD+UR configuration and about migrating the UR environment or the GAD+UR using GAD, see the Global-Active Device User Guide.

Global storage virtualization

Pairs can be created using volumes in a virtual storage machine. Note the following:

Though Device Manager - Storage Navigator displays the virtual LDEV ID of a volume belonging to a virtual storage machine, make sure when running pair operations in Device Manager - Storage Navigator that you specify the physical LDEV ID.
A volume’s virtual ID used with Universal Replicator cannot be deleted.

LUN Manager

LUN Manager operations do not affect Universal Replicator operations. The following volumes can also be assigned to UR pairs:
- Volumes that are under secure ports assigned to host groups or iSCSI targets
- Volumes that are protected by namespace security of NVMe-oF
UR pair volumes can be protected by LUN Manager or namespace security.
Universal Replicator S-VOLs cannot be accessed by any UNIX® or PC server host except when the pair is split.

Resource Partition Manager

You can specify Resource Partition Manager volumes as UR P-VOL and S-VOL as long as they belong to the same resource group. For journal volumes, use a Resource Partition Manager OPEN-V virtual volume.

For details, see the Provisioning Guide for your storage system.

Thin Image

Universal Replicator pair volumes can be shared with Thin Image (TI) P-VOLs, with limitations on how they can be used together.

A UR P-VOL or S-VOL can be used as a TI P-VOL.
A UR P-VOL or S-VOL that is part of a delta resync configuration with TrueCopy can also be used as a TI P-VOL.
A TI P-VOL cannot be specified as an S-VOL when creating a UR pair. However, you can specify a TI P-VOL as an S-VOL when creating a UR delta resync pair in a 3DC multi-target or 3DC cascade configuration with three UR sites.

UR basic configuration with TI

The UR pair must be created before the secondary site TI pair.

3DC cascade configuration with TI

The TC pair must be created before the intermediate TI pair.
The UR pair must be created before the secondary site TI pair.

3DC multi-target configuration with TI

You can create either the TC pair or the primary site TI pair first.
The TC pair must be created before the secondary site TI pair (campus distance).
The UR pair must be created before the secondary site TI pair (metro distance).

Delta Resync configuration with TI

The TC, UR, and UR delta resync pairs must be created before the secondary site TI pairs.
You can create a primary site TI pair before or after the delta resync pairs.
For the 3DC multi-target delta resync configuration and the 3DC cascade delta resync configuration with three UR sites, first you need to create the 3DC multi-target configuration or the 3DC cascade configuration. You need to create the UR pairs before the TI pair in a "URxUR" 3DC delta configuration. You do not need to create the UR delta resync pair before the TI pairs at the secondary site.

Universal Volume Manager

You can create UR pairs using Universal Volume Manager-configured volumes.

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

Virtual LUN

Universal Replicator supports the Virtual LUN feature, which allows you to configure custom-size LU that are smaller than standard-size LUs. When custom-size LUs are assigned to a Universal Replicator pair, the S-VOL must have the same capacity as the P-VOL.

To perform Virtual LUN operations on a pair’s P-VOL and S-VOL, the pair must be deleted and the volumes’ status returned to SMPL.

Volume Migration

You can specify the Universal Replicator P-VOL or S-VOL as Volume Migration source volumes. However, when UR pair status is COPY or PAIR, do not perform the volume migration operation; otherwise, the operation is stopped.

UR pair volumes and journal volumes cannot be used as Volume Migration target volumes.

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