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Monitoring and maintenance

To maintain your system, you must know about monitoring, editing, and maintenance for external volumes, paths, and systems.

Monitoring external volumes and paths

You can view system details about mapped external volumes, the ports used, and the external paths.

Before you begin

  • You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select one or more external volumes, and then select View External LUN Properties.

External volume policy settings and functions

When you map an external volume to an internal volume, mapping policies are used. To change the mapping policies, you need to edit the default mapping settings. You can change default mapping settings without affecting the settings in previously mapped volumes.

  • Base Emulation Type ()Specify OPEN-V to use existing data in an external volume from VSP G1000, VSP G1500, and VSP F1500.

    If you use an emulation type other than OPEN-V, the volume requires a specific area for management data. This results in a volume capacity after mapping that is less than the actual external volume capacity. For more information about calculating the capacity of external volumes, see Capacity requirements for volumes.

  • Cache ModeI/O to and from the local storage system always uses cache. Write operations are always backed up in duplex cache. The Cache Mode setting specifies whether write data from the host is written to the external volume asynchronously (Enable) or synchronously (Disable).
    • Enable: After receiving the data into the local system's cache memory, the system signals the host that the I/O operation has completed, and then asynchronously destages the data to the external volume.
    • Disable (default): After synchronously writing the data to the external volume, the local system signals the host that an I/O operation has completed.

    For additional information, see Cache use and external storage performance.

  • Cache PartitionCache memory can be partitioned by using Virtual Partition Manager to configure a cache logical partition (CLPR) for the mapped volumes. Cache logical partitions are often used to limit cache-use by accessing slower external storage volumes.

    We strongly recommend that you place external storage array groups in a CLPR other than CLPR0. For details about CLPR, see the Performance Guide.

  • Inflow ControlWhen the write operation to the external volume cannot be completed, Inflow Control specifies whether the write operation to cache memory is limited (Enable) or continued (Disable).
    • Enable: The write operation to cache is limited and I/O from the host is not accepted. Limiting the write operation prevents the accumulation of data that cannot destage to cache memory.
    • Disable (default): I/O sent from the host during the retry operation is written to cache memory. When write operations to the external volume are again possible, data in cache memory is destaged to the external volume.
  • Use ALUA as Path Mode

    In the local storage system, you can select whether ALUA mode is used as the path mode. If ALUA is supported in the profile information of the external storage, Enable is used by default. Otherwise, Disable is used. For information on ALUA mode, see Supported external system path mode for external volumes .

  • Load Balance Mode Select Depends on the selected external volume(s), Normal Round-robin, Extended Round-robin, or Disable as a Load Balance Mode for the external storage system. By default, Normal Round-robin (recommended) is set. However, when the product name of the storage system is displayed as (generic), Depends on the selected external volume(s) is used by default.

    If Single is set as the Path Mode or Disable is set for Use ALUA as Path Mode, Load Balance Mode cannot be specified.

    • Depends on the selected external volume(s)If Enable is set for ALUA Settable on the external volume, Normal Round-robin is set for Load Balance Mode automatically. If Disable is set for ALUA Settable, Disable is set for Load Balance Mode automatically.
    • Normal Round-robinI/O is distributed to several paths on which I/O operation is enabled for the external storage system.
    • Extended Round-robinI/O is distributed to several paths on which I/O operation is enabled for the external storage system. For sequential I/O, the external volume is divided into sections at regular intervals. In this case, the same path is used for I/O within the same section which reduces the frequency of I/O distribution.
    • DisableAs in Single mode, I/O operation is performed using the path that has the highest priority of all paths on which I/O operation is enabled for the external storage system.
  • CLPRSpecify CLPR when accessing a mapped volume if cache memory is split in Virtual Partition Manager. For detailed information, refer to the Performance Guide.

Editing mapping policies for external volumes

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. In the External Storage window, click the External Paths tab.

  3. On the External Paths tab, select a path group.

  4. Click More Actions and select Edit Policies.

  5. In the Edit Policies window, make whatever changes are required to the external volume settings.

  6. Click Apply.

    GUID-FFF87993-B1E7-4DCD-B379-50728C68EF7A-low.png
    NoteYou can also edit Cache Mode and Inflow Control for individual external volumes. In Device Manager - Storage Navigator, select an external volume in the Mapped Volumes tab, and then click Edit External Volumes.

Changing the MP unit of an external volume

Before you begin

  • You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select one or more external volumes, and then select More Actions >Assign MP Unit.

  5. In the Assign MP Unit window, select the desired MP unit.

    The current setting for the external volume is displayed, unless you have selected multiple external volumes with different values. Then the field is blank.

    The choices you see are dependent on the configuration of the device.

    NoteMP unit assignment should be set to evenly distribute work across all the available processors.

    Selecting Auto allows the system to assign the unit.

  6. Click Finish.

  7. In the Confirm window, review the settings, accept the task name or enter a new one, and then click Apply.

Changing path mode to ALUA mode (Enable or Disable)

You can select whether ALUA mode is used as the path mode. See Supported external system path mode for external volumes .

Before you begin

  • The external storage system must support ALUA. If Enable is set for ALUA Settable on the external volume, Enable is set for Use ALUA as Path Mode automatically. If Disable is set for ALUA Settable, Disable is set for Use ALUA as Path Mode automatically.
  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select an external volume, and then click Edit External Volumes.

  5. On the Edit External Volumes window, select Enable or Disable as the Use ALUA as Path Mode property.

  6. Click Finish to display the Confirm window.

  7. Confirm the settings and enter the task name in the Task Name box.

  8. In the Confirm window, click Apply.

Changing I/O mode for external storage systems

With Load Balance Mode settings, you can change the I/O mode for external storage systems for each of the external volumes.

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select an external volume, and then click Edit External Volumes.

  5. On the Edit External Volumes window, select the Load Balance Mode property, and then click Extended Round-robin, Normal Round-robin, or Disable.

  6. Click Finish to display the Confirm window.

  7. Confirm the settings and enter the task name in the Task Name box.

  8. In the Confirm window, click Apply.

Changing the port settings of an external storage system

You can change the port settings of an external system.

For Fibre Channel ports, use the Edit External WWNs window. For iSCSI ports, use the Edit External iSCSI Targets window.

However, note the following:

  • If the current setting is error-free, it is best to continue using it.
  • For an external volume with normal I/O, set I/O Timeout from 5 - 15 seconds.
  • Use the external system's recommended values for other port settings.
  • If you are going to change several parameters for the same external WWN or the same external iSCSI target, ensure that a task is completed before you perform the next task. If you perform a new task before the prior task is completed, the prior task might not be applied.

Before you begin

  • You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Paths tab, select a port, and then open the window for editing port settings.

    • For a Fibre Channel port, click Edit External WWNs.
    • For an iSCSI port, click More Actions Edit External iSCSI Targets.
  3. In the Edit External WWNs or Edit External iSCSI Targets window, change the desired settings.

    NoteThe current values for the external WWN display unless you have selected multiple paths with different values. Then the fields are blank.
  4. Click Finish.

  5. In the Confirm window, review settings, accept the task name or enter a one, and then click Apply.

Path maintenance

You can add external paths to a path group, change a path's priority, disconnect and reconnect paths (which must be performed before removing or replacing paths), remove or replace a path, or replace all paths.

The following topics provide instructions.

Adding an external path to an existing path group

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, select a path group.

  4. Click Edit External Path Configuration.

  5. In the Edit External Path Configuration window, select an external path or paths from the Available External Paths list and click Add.

    If the External Storage System or the External WWN that you want is not available in the dialog box, click Discover External Target Ports and add the port that connects to the WWN.
  6. To change the priority of external paths, click Raise Priority or Lower Priority in the Selected External Paths list.

  7. Click Finish.

  8. In the Confirm window, review settings, accept the task name or enter a new one, and then click Apply.

Adding an iSCSI path

Before you begin

You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. In the External Storage window, click the iSCSI Paths tab, and then click Add iSCSI Paths.

  3. Click Discover iSCSI Targets.

    The Discover iSCSI Targets window displays.
  4. For Local Port ID, select the port connected to the external storage system of the local storage system.

  5. For Remote IP Address, enter the IP address of the external storage system port.

  6. For Remote TCP Port Number, enter the TCP Port Number of the external storage system port (1 to 65535).

  7. Click Add.

    The targets that you entered will be added to the Discovery List table. You can add up to eight targets.
  8. Click OK.

    The Add iSCSI Paths window displays.
  9. Select the iSCSI path to be added from the Available iSCSI Paths table.

  10. For Authentication Method, select CHAP or None.

    For either authentication method, select one of the following options for Mutual CHAP:

    • Enable: Authentication is bidirectional
    • Disable: Authentication is unidirectional

    If you select CHAP and enable mutual CHAP, you must specify a user name and secret. If you disable mutual CHAP, the user name and secret are optional.

  11. Click Add.

    The selected iSCSI path will be added to the Selected iSCSI Paths table.

    Up to 4,096 iSCSI paths can be added including those paths that were already added.

  12. Click Finish.

  13. In the Confirm window, check settings, enter a task name, and then click Apply.

    Tip

    To display the Tasks window automatically, select Go to tasks window for status then click Apply.

  14. Check the result in the Tasks window. You can suspend or cancel the task if the task is not executed.

Editing an iSCSI target

Before you begin

  • You must have the Storage Administrator (Provisioning) role.
  • Make sure that I/O operations are not being performed on the host.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. In the External Storage window, click the iSCSI Paths tab, and then click Edit iSCSI Targets.

  3. For Authentication Method, select CHAP or None.

    For either authentication method, select one of the following options for Mutual CHAP:

    • Enable: Authentication is bidirectional
    • Disable: Authentication is unidirectional

    If you select CHAP and enable mutual CHAP, you must specify a user name and secret. If you disable mutual CHAP, the user name and secret are optional.

  4. Click Finish.

  5. In the Confirm window, check settings, enter a task name, and then click Apply.

    Tip

    To display the Tasks window automatically, select Go to tasks window for status then click Apply.

  6. Check the result in the Tasks window. You can suspend or cancel the task if the task is not executed.

Changing external path priority

You can change the priority of your primary and alternate external paths, moving them higher or lower depending on your requirements. See External paths for more information on path priorities for Single and Multi mode.

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, select a path group.

  4. Click Edit External Path Configuration.

  5. In the Edit External Path Configuration window, in the Selected External Paths list, select the desired path and click Raise Priority or Lower Priority.

  6. Repeat the previous step to continue moving the path higher or lower. Move other paths as needed.

  7. Click Finish.

  8. In the Confirm window, review settings, accept the new task name or enter a new one, and then click Apply.

Executing a login test for an iSCSI target

Before you begin

  • You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. In the External Storage window, click the iSCSI Paths tab.

  3. Select the iSCSI path for which you want to execute a login test, then click Test Login iSCSI Target.

Disconnecting an external path

You can disconnect all external paths connected either to a port on the local system or to a WWN on an external system. Disconnecting paths affects the external volumes mapped using the port.

An external path is disconnected for the following reasons:

  • Before removing a path
  • To replace a path or switch
  • To perform maintenance on a path
  • To perform maintenance on the external system or volume

Before you begin

  • When you disconnect a path, make certain that alternate paths are available for mapped external volumes using the path.
  • You must have the Storage Administrator (Provisioning) role.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. Click the External Paths tab.

  3. On the External Paths tab, select a path group.

  4. Click Disconnect External Paths.

  5. In the Disconnect External Paths window, select one of the following:

    • For Fibre Channel ports, select either By Ports or By External WWNs.
    • For iSCSI ports, select either By Ports or By External Storage Ports.
  6. Click Finish.

  7. In the Confirm window, review settings, accept or enter a new task name, and then click Apply.

Deleting an iSCSI path

Before you begin

  • You must have the Storage Administrator (Provisioning) role.
  • The specified iSCSI path must not be used as an external path by Universal Volume Manager.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. In the External Storage window, click the iSCSI Paths tab.

  3. Select the iSCSI path that you want to delete, and then click Delete iSCSI Paths.

  4. Check settings, enter a task name, and then click Apply.

    Tip

    To display the Tasks window automatically, select Go to tasks window for status then click Apply.

  5. Check the result in the Tasks window. You can suspend or cancel the task if the task is not executed.

Reconnecting an external path

You can reconnect an external path that was disconnected. You reconnect paths either to a port on the local system or to a WWN on the external system. When you reconnect, original path settings are restored.

Before you begin

  • Make sure the path is in a status that can be restored.
  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. Click the External Paths tab.

  3. On the External Paths tab, select a path group.

  4. Click Reconnect External Paths.

  5. In the Reconnect External Paths window, select one of the following:

    • For Fibre Channel ports, select either By Ports or By External WWNs.
    • For iSCSI ports, select either By Ports or By External Storage Ports.
  6. Click Finish.

  7. In the Confirm window, review settings, accept the task name or enter a one, and then click Apply.

Changing the cache mode setting of the external volume

You can change the cache mode of the external volume in the Edit External Volumes window.

If the system cannot communicate with external volumes, the Inflow Control setting specifies whether the write operation to cache is limited (Enable) or continued (Disable). Disable is set by default. You can change the setting in the Edit External Volumes window. If you are using a Thin Image pool, all external volumes in the same pool must use the same Cache Mode setting.

Before you begin

  • Storage Administrator (Provisioning) role
  • Before changing the cache mode of the external volume, review each item listed in the following table.

Item to Review

Description

Cache mode and pool volumes

When a volume is registered to a pool as a pool volume, the cache mode setting should be the same among all the pool volumes in the pool.

Cache mode and remote command devices

When the volume is a remote command device, you cannot change the cache mode from Disable to Enable.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external storage system.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select an external volume, and then click Edit External Volumes.

  5. On the Edit External Volumes window, select the Inflow Control property, and then click Enable or Disable.

  6. Click Finish to display the Confirm window.

  7. Confirm the settings and enter the task name in the Task Name box.

  8. In the Confirm window, click Apply.

Removing or replacing an external path

You can remove a path so it is no longer available to the external volume. You remove a path to replace it with another external path or to perform maintenance on the physical link.

NoteIf all external paths are not removed before detaching a channel adaptor, the channel adaptor cannot be detached.

Before you begin

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system.

  3. On the External Path Groups tab, select a path group.

  4. Click Edit External Path Configuration.

  5. In the Edit External Path Configuration window, in the Selected External Paths list, select the path to be removed, and then click Remove.

  6. Click Finish.

  7. In the Confirm window, review settings, accept or enter a new task name, and then click Apply.

    If you are replacing the path, see Adding an external path to an existing path group .

Replacing all external paths

You can replace the primary and alternate paths used by an external volume. Doing this requires one path to remain in Normal status at all times.

The following figure shows one path used by an external volume remaining in a Normal status at all times.

GUID-424AA103-8D3F-4F8A-B5D0-ABFACB82644D-low.png

Procedure

  1. Disconnect external path A. See Disconnecting an external path .

  2. Disconnect the cable for external path A, then remove it. See Removing or replacing an external path .

  3. Make sure the cable for external path C is connected, and then add this path to an existing path group. See Adding an external path to an existing path group .

    When external path C status is Normal, then both external path B and external path C are set, and you can replace the next path.
  4. Disconnect external path B.

  5. Disconnect the cable for external path B, then remove it.

  6. Make sure the cable for external path D is connected, and then add this path to an existing path group.

    When external path D status is Normal, then both external path C and external path D are set. The paths have all been replaced.

Disconnecting external systems and volumes

You can disconnect a single mapped external volume, or all the mapped volumes in an external system. You disconnect all volumes by disconnecting the system itself.

You disconnect a volume or system in order to perform the following operations:

  • Turn off the power supply of the local or external storage system
  • Delete an external volume's mapping
  • Access a mapped external volume or volumes from the external storage system

When you disconnect volumes, they stop accepting host I/O and all data in the cache memory is destaged to the volumes. The mapping settings are also preserved. When the volumes are reconnected, they are assigned the same settings.

When you disconnect an external system, the mapped external volumes in the system are also disconnected. This is the primary method for disconnecting all the mapped volumes in an external system.

Prerequisites for disconnecting external systems

Before disconnecting volumes or systems, processes must be resolved or stopped, as described in the following table.

Activity in the external volume

Required operation

I/O to the external volume from the open system host is in progress.

Stop I/O to the volume and un-mount the volume from the host.

Host I/O is forcibly stopped if you disconnect when I/O is in progress.

The external volume includes LDEVs used in pair operations with the following copy software products:

  • ShadowImage
  • Universal Replicator
  • TrueCopy
  • Thin Image
  • Global-active device

Delete the pair.

You can disconnect without deleting a ShadowImage pair when pair status is PSUE or Suspend/SUSPER.

The external volume includes LDEVs registered to a Thin Image data pool.

Delete Thin Image data pool.

The external volume includes LDEVs registered to a Dynamic Provisioning pool volume (DP-VOL).

Perform all of the following operations on DP-VOLs associated with the external volume:

  • Stop using the DP-VOLs.
  • Use the Block LDEVs window to block the DP-VOLs.
  • If the Data Direct Mapping attribute is enabled for the external volume, block only the related DP-VOL.
  • When a virtual volume for which Compression or Deduplication and Compression is enabled is created from a DP pool, if a failure occurs in the pool-VOL registered in the pool, recover the failure of the pool-VOL. In addition, if a deduplication system data volume is created, block it.

The external volume includes LDEVs for which Volume Migration processing is in progress.

Delete the migration plans.

The external volume is used in a global-active device quorum disk.

Delete the quorum disk settings.

Disconnecting an external storage system, all mapped volumes

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, select a path group.

  3. Click Disconnect External Storage Systems.

  4. In the Disconnect External Storage Systems window, review the volumes that will be disconnected, then click Apply.

    GUID-3CBE3A6C-53CB-425F-B9EB-CAEDE10D187A-low.png
  5. In the Confirm window, click Apply again.

Results

When you finish the procedure, the status of the external volume displays as Cache Destage, even if there is no data left in the cache. You can click Refresh View to update the status. When processing is completed, the status of the volume changes to Disconnect.

Disconnecting a single mapped volume

Before disconnecting a mapped volume, review Prerequisites for disconnecting external systems.

Before you begin

  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for the storage system with the volume to be disconnected.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select the row for the volume you want to disconnect.

  5. Click More Actions and select Disconnect External Volumes.

  6. In the Disconnect External Volumes window, select the row of the volume to be disconnected, accept the task name or enter a new one, and then click Apply.

  7. Click Apply in the Confirm window.

Results

When you finish the procedure, the external volume's status displays as Cache Destage, even if there is no data left in the cache. You can click Refresh View to update the status. When processing is completed, the volume's status changes to Disconnect.

Deleting an external volume mapping

If you no longer want to access data in an external volume, you can delete the mapping. When you do, the data in the external volume is not deleted.

Before you begin

  • If you disconnect the external volume or volumes, before you delete them, all the data in the cache memory is written to the external volume.

    However, you can delete a volume without disconnecting, meaning that data in cache memory is not destaged to the external volume.

  • You cannot delete a mapping while the external volume is used in the following:
    • TrueCopy, Universal Replicator, ShadowImage, Thin Image, or global-active device.
    • A reserved volume for ShadowImage or Volume Migration.
    • A pool-VOL
    • A Quorum Disk
  • For command devices, stop the application using the external volume as a command device.
  • Storage Administrator (Provisioning) role

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for an external system

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select the external volume.

  5. Click More Actions and select Delete External Volumes.

  6. In the Delete External Volumes window, verify the external volumes you want to delete.

    GUID-8814AC20-0D87-435A-B694-822A6DEC3BA5-low.png
  7. For Have you already disconnected external volume of above table?, click one of the following:

    • Yes if you have already disconnected the volumes.
    • No if you have not disconnected the volumes.
  8. If you clicked No in the previous step, then, for Do you want to execute Delete External Volumes operation without writing the cache data to the volumes?, click Yes or No.

  9. Click Finish.

  10. In the Confirm window, review settings and accept the task name shown or enter a new one. When satisfied click Apply.

Reconnecting external systems and volumes

After you disconnect an external system or volumes, you must reconnect them before you can start using them again.

When you reconnect external systems or volumes, the preserved mapping settings and path statuses are compared to the current statuses. When the statuses and settings match, each volume is mapped, placed in Normal status, and is available for I/O operations. However, if an external volume is not ready to be resumed, the status of the disconnected volume is Blockade. If this problem occurs, see General troubleshooting .

Reconnecting an external storage system and all mapped volumes

When you reconnect an external system, all mapped volumes in the system are also reconnected. This is the primary method for reconnecting disconnected volumes in an external system.

Before you begin

  • You must have the Storage Administrator (Provisioning) role to perform this task.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, select the row for the external system to be reconnected, and then click Reconnect External Storage Systems.

  3. In the Reconnect External Storage Systems window, check the volumes to be reconnected, accept or enter a new task name, and then click Apply.

  4. In the Confirm window, click Apply again.

Results

When you finish the procedure, the status for each external volume displays as Checking, then Normal. If the external storage system cannot be reconnected, the status becomes Blockade.

Reconnecting a single mapped volume

Before you begin

  • You must have the Storage Administrator (Provisioning) role to perform this task.

Procedure

  1. Open the External Storage window.

    1. Click Storage Systems, and then expand the Storage Systems tree.

    2. Click External Storage.

  2. On the External Storage Systems tab, click the link for the storage system with the volume to be reconnected.

  3. On the External Path Groups tab, click the link for a path group.

  4. On the Mapped Volumes tab, select the external volume.

  5. Click More Actions and select Reconnect External Volumes.

  6. In the Reconnect External Volumes window, select the row of the volume to be reconnected, and then accept or enter a new task name.

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  7. Click Apply in the Confirm window.

  8. When you finish the procedure, the external volume status displays as Checking, and then Normal. If the volume cannot be resumed because the mapped settings and the external volume status are not in sync, the status becomes Blockade.

Requirements for external storage system maintenance

You must have the Storage Administrator (Provisioning) role. Before making changes to the external system, you must disconnect the external system and delete external volume mapping. After you have completed the changes, you can reconnect the system and remap the external volume.

You must remove and remap the external volume before making any of the following changes to the external system:

  • Changing WWNs/iSCSI target names of all target ports that connect to the local storage system
  • Changing the serial number of the external system
  • Changing LUNs of volumes in the external system
  • Reducing the volume capacity of the external volume
  • Modifying a host that is directly connected to a external storage system.

To modify the WWNs/iSCSI target names of some target ports connected to the local storage system, you do not need to release volumes mapped to the local storage system.

Changing the WWNs/iSCSI target names of the external storage system without deleting the external volume mapping

Procedure

  1. Change the WWN/iSCSI target name of the external storage.

    See the Provisioning Guide for detailed procedures. Changing the WWN/iSCSI target name blocks the external path that uses the target port with a WWN/iSCSI target name that has been changed.
  2. Add an external path between the local storage system and target port with a WWN/iSCSI target name that has been changed.

  3. Delete the external path that was blocked in step 1.

Next steps

Before deleting external volume mapping, make sure that the volume has no LU paths and is not part of a copy pair. See Deleting an external volume mapping for instructions.

Powering off and on storage systems

This section provides procedures for powering off and on local and external storage systems.

Powering off and on external storage systems

If you power off and on the external storage system when the local storage system is on, the following Universal Volume Manager operation is required.

Disconnect External Storage Systems: Run this command before you perform maintenance on an external storage system or perform a scheduled shutdown. When Disconnect External Storage Systems is selected, the I/O response from hosts of external volumes mapped as a local storage system volumes will stop. Next, data for each external volume is destaged from the cache memory of the local storage system to the external volume.

Tip The same task can be performed on individual volumes with the Disconnect External Storage Volumes command. External volume mapping can be removed by running Disconnect External Storage Volumes followed by the Delete External Volumes command.

Reconnect External Storage Systems: Run this command to determine whether the defined configuration information of external volumes mapped as local storage system volumes matches the status of the external volumes. If external volumes can be used as mapped volumes, I/O to the external volumes is accepted, and the volumes can be used again.

The Reconnect External Storage Systems command is used to recover from an I/O failure after the Disconnect External Storage Systems command has been run.

If there are any path issues, they must be resolved before you run this command.

TipTo perform the same task on individual volumes, use the Reconnect External Volumes command.
When you run the Reconnect External Storage Systems or Reconnect External Volumes command, if external volumes can be used, I/O to the external volumes is accepted and the volumes can be used again. If an external volume cannot be used, its status is Blockade.

Powering off external storage systems (scheduled shutdown)

Before you begin

  • You must have the Storage Administrator (Provisioning) role to perform this task.
  • For details about the Block LDEVs window, see the Provisioning Guide.

Procedure

  1. Stop read and write I/O operations to the external volume that is mapped as the local storage volume in the external storage system that you want to power off.

  2. If the external volume is defined as a DP-VOL in the local storage system, block all DP-VOLs for maintenance. If not, skip the following steps, and go to step 3.

    1. Open the Pools window.

      i. Click Storage Systems, and then expand the Storage Systems tree.

      ii. Click Pools.

    2. On the Pools tab, click the link for the pool you want to block.

    3. Select the Virtual Volumes tab.

    4. Click Select All Pages.

    5. On the menu bar, click Actions, Logical Device, and then Block LDEVs.

    6. In the Block LDEVs window, confirm the settings and enter the task name in the Task Name box.

    7. Click Apply in the Confirm window.

  3. Perform the Disconnect External Storage Volumes command for the external systems you want to power off.

    I/O operations to the external volumes are not allowed, and data in cache memory of the local storage system is written to the external volumes.
  4. Perform any other operations required for powering off the external storage system.

  5. Power off the external storage system.

    TipAfter disconnecting external storage volumes, if you want to use mapped external volumes again as the local storage volumes, you must reconnect the external storage systems.

Reconnecting external storage systems after powering off

After you run the Disconnect External Storage Volumes command, and then power off an external storage system, you cannot access external volumes from the local storage system even if you power on the external storage system again. To access the external storage system again, you must run the Reconnect External Storage Systems command. This process checks whether the defined configuration information of external volumes mapped as local storage volumes matches the status of the external volumes. If external volumes can be used as mapped volumes, I/O operations to the external volumes are accepted, and the volumes can be used again.

Before you begin

  • You must have the Storage Administrator (Provisioning) role to perform this task.
  • For details about the Block LDEVs window, see the Provisioning Guide.

Procedure

  1. Power on the external storage system.

  2. Reconnect the external system.

    For details, see Reconnecting external systems and volumes.
  3. If any external volumes were defined as DP-VOLs in the local storage system, use the steps listed in the following procedure to restore all blocked DP-VOLs.

    1. Open the Pools window.

      i. Click Storage Systems, and then expand the Storage Systems tree.

      ii. Click Pools.

    2. On the Pools tab, click the link for the pool you want to block.

    3. Select the Virtual Volumes tab.

    4. Click Select All Pages.

    5. On the menu bar, click Actions, Logical Device, and then Restore LDEVs.

    6. In the Restore LDEVs window, confirm the settings and enter the task name in the Task Name box.

    7. Click Apply in the Confirm window.

Powering off and on local storage systems

When you power off the local storage system, data for each external volume is destaged from the cache memory of the local storage system to the external volume.

Powering off local storage systems (scheduled shutdown)

  1. Stop read and write I/O to the local storage system.

  2. Split all pairs that use external volumes.

    For information on pairsplit operations, see the user guide for the relevant software.
  3. Confirm that the status of each external volume is Normal or Disconnect.

  4. Perform any other operations required for powering off the external storage system.

  5. Turn off the power supply of the local storage system.

Reconnecting local storage systems after powering off

When you disconnect external storage systems, and then power off the local storage system, you cannot access the external volume from the local storage system if you power on the external storage system again. To access the external storage system, you must run the Reconnect External Storage Systems command. This procedure checks whether the defined configuration information of each external volume mapped as a local storage volume matches the status of the external volume. If the external volume can be used as a mapped volume, I/O operations to the external volume are accepted, and the volume can be used again.

When you run the Disconnect External Storage Volumes or Disconnect External Volumes command, and all data stored in the cache memory is written to the external volumes, the external volume status displayed in the window changes to Disconnect.

Procedure

  1. Power on the local storage system.

  2. Resynchronize all pairs.

    For information on resynchronizing pairs, see the user guide for the relevant software.
  3. Start I/O operations to the local storage system.

Powering off and on local and external storage systems

When you power off the local system, data for each external volume in the cache memory of the local system is written to the external volume.

You do not need to disconnect the external system when powering off only the local system. However, if you do disconnect the external system, when you power on the local system again, access is disabled to the external system until you reconnect the external system.

You must temporarily halt Universal Volume Manager operations before powering off external storage systems. When the systems are powered on, you can resume all operations.

Steps in the procedures of this topic must be followed in this order:

  1. When you power off the local and external systems, the local system must be turned off first before the external system.
  2. When you power on both systems, the external system must be turned on first before the local system.

Powering off local and external storage systems

  1. Stop read or write I/O operations to the local storage system.

  2. Split all pairs that use external volumes.

    For information on pairsplit operations, see the user guide for the relevant software.
  3. Confirm that the status of each external volume is Normal or Disconnect.

  4. Power off the local storage system.

    Wait for the local system to completely power off.
  5. Power off the external storage system.

Powering on local and external storage systems

Procedure

  1. Power on the external storage system.

    Wait for the external storage system to completely power on.
  2. Power on the local storage system.

    Wait for the local storage system to completely power on.
  3. Resynchronize all pairs.

    For information on resynchronizing pairs, see the user guide for the relevant software.
  4. Start read or write I/O operations to the local storage system.