Troubleshooting pools, pairs, and volumes related to Thin Image Advanced

Pool information is not displayed.

Cause: The pool is blocked.

Solution: Recover the blocked pool (see Workflow for recovering blocked pools).

You cannot create HTI Advanced pairs.

Causes:

• The number of cache management devices is insufficient.
• You have not met the prerequisites to create the pair.
• The status of the specified volume is not displayed because you are deleting the HTI Advanced pair.
• The pool warning threshold is exceeded.

Solutions:

• Secure sufficient cache management devices for creating HTI Advanced pairs (see Calculating the number of cache management devices).
• If cache management devices are depleted, perform one of the following:
  • Delete unnecessary external volumes.
  • Delete unnecessary V-VOLs.
  • Delete all HTI Advanced pairs related to the P-VOL.
• Ensure that the conditions for creating the HTI Advanced pair are satisfied before trying to create the pair again.
  1. Check that the volume specified is a DRS-VOL (DRS is displayed for VOL_ATTR) using the raidcom get ldev -ldev_id command.
  2. Check that the capacity of the volume is the same as the P-VOL.
• Check that the status has changed from pair deletion in progress (SMPP is displayed for STAT) to unpaired volume (the volume is not displayed in the list of pairs) by using the raidcom get snapshot -key detail command. Then, try to create the pair again.
• Check that the volume specified is not being used by HTI Advanced (QS is not displayed for VOL_ATTR) using the raidcom get ldev -ldev_id command, then try to create the pair again.
• If SIM code 62B000 is reported, the DP pool warning threshold might be exceeded. See the list of SIM codes in the Provisioning Guide for your storage system. From the listed solutions for SIM code 62B000, perform the applicable one.

Causes:

• The internal resources for your HTI Advanced pair are temporarily depleted.
• The pool is full.

Solutions:

• When SIM code 62Axxx is not reported,
  • Accelerate the collection of internal resources by adjusting the I/O load and minimizing the load on the MP unit the applicable pair belongs to.
  • Extend the interval between splitting operations for the pairs containing the applicable P-VOL.
• When SIM code 62Axxx is reported,
  • The pool might be full. See the list of SIM codes in the Provisioning Guide for your storage system. From the listed solutions for SIM code 62Axxx, perform the applicable one.

Cause: The internal resources for your HTI Advanced pair are temporarily depleted.

Solutions:

• Accelerate the collection of internal resources by adjusting the I/O load and minimizing the load on the MP unit the applicable pair belongs to.
• Extend the interval between splitting operations for the pairs containing the applicable P-VOL.

HTI Advanced pairs are not displayed in the volume list.

Cause: You have not created the HTI Advanced pairs.

Solution: Create the HTI Advanced pairs.

Copying metadata failed during pair restoration. The status changed to PSUE and SIM code 4B3xxx (PSUE occurrence) was issued regardless of whether the failure was drive-related.

Cause: Copying metadata failed while restoring an HTI Advanced pair. In this case, only the pair being restored enters the PSUE status. Other HTI Advanced pairs are not affected.

Solution: For details about how to restore an HTI Advanced pair that enters the PSUE status during restoration, contact customer support.

A volume is blocked.

Causes:

• A failure occurred in at least two data drives.
• The breaker was turned off once and then the power supply switched on.

Solution: Contact customer support.

Expansion of volume capacity failed.

Cause and solution: If expansion of volume capacity failed, see Troubleshooting the expansion of Thin Image Advanced pair volume capacity for the solution.

A problem occurred in the host application for monitoring the volumes.

Cause: Access to the volume is rejected.

Solutions:

• Complete the following:
  1. Stop the host application monitoring the volumes.
  2. Split all of the pairs ("PSUS" status or an unpaired volume) (see Splitting Thin Image Advanced pairs to store snapshot data).
  3. Start the monitoring application on the host and check whether the host has access to pair volumes (see Thin Image Advanced host access and pair status).
• Check the Data Retention Utility access attributes and determine whether you have permission to access the target volume.

A virtual volume cannot be recognized correctly after the host server is booted/rebooted or the command for recognizing a device is performed.

Cause: Access to the volume is rejected.

Solutions:

• Complete the following:
  1. Stop the host application monitoring the volumes.
  2. Split all of the pairs ("PSUS" status or an unpaired volume) (see Splitting Thin Image Advanced pairs to store snapshot data).
  3. Reboot the host server or run a command that causes the system to recognize the device.
  4. Start the monitoring application on the host and check whether the host has access to pair volumes (see Thin Image Advanced host access and pair status).
• Check the Data Retention Utility access attributes and determine whether you have permission to access the target volume.

The host computer attempts to access the port and an error occurs.

Cause: A port may go offline because access to a volume on another port has been rejected.

Solutions:

• Wait until the process has completed, and then retry the task.
• If a host application is installed to monitor the volume, stop the application.
• Check the Data Retention Utility access attributes and determine whether you have permission to access the target volume.

HDvM - SN times out frequently.

Cause: HDvM - SN cannot respond to the SVP because the load is too heavy.

Solution: Wait until the process has completed and then retry the task.

The raidcom get snapshot -key detail command does not update pair information or the raidcom get snapshot -key detail -format time command does not update split time (SPLT-TIME).

Cause: HTI Advanced processing may be in progress.

Solution: Wait until the HTI Advanced processing finishes and the update completes.

After a host completes a write operation, the used pool capacity shown by the raidcom get pool -key basic command (Snap_Used (MB)) and the used pool capacity shown by the raidcom get ldev -ldev_id command for the specified P-VOL (Snap_Used_Pool (MB)) do not match.

Cause: The copy processing is running.

Solution: Wait until the copy processing is completed. The used pool capacity shown by the raidcom get pool -key basic command (Snap_Used (MB)) and the used pool capacity shown by the raidcom get ldev -ldev_id command for the specified P-VOL (Snap_Used_Pool (MB)) will match.

Causes: If an attempt to create a DRS-VOL fails, an incorrect DRS-VOL might be created, with Enabling as the capacity saving status. If one of the following operations is performed for this incorrectly created volume, the operation fails:

• Creation of an LU path
• Setting of the volume as a command device
• Formatting of the volume
• Pair operation
• Expansion of capacity

Solution:

1. Delete the incorrectly created DRS-VOL.

   If you use the raidcom delete ldev command to delete it, run the command with the -operation initialize_capacity_saving option.

2. Create a new DRS-VOL.
3. Perform the previously failed operation on the volume created in step 2.

You cannot resynchronize an HTI Advanced pair.

Cause: The HTI Advanced pair cannot be defined because the pair entered the PSUE status while being created.

Solution:

1. Delete the suspended HTI Advanced pair (PSUE status) (see Deleting Thin Image Advanced pairs.
2. Create the HTI Advanced pair (see Creating Thin Image Advanced pairs).