Troubleshooting Dynamic Provisioning

Provisioning Guide for VSP One Block

Version
10.2.x
Audience
anonymous
Part Number
MK-23VSP1B012-00
The following table provides troubleshooting information for Dynamic Provisioning.

If you are unable to solve a problem, or if you encounter a problem not listed, contact customer support.

Problem Causes and solutions
Cannot create a V-VOL. Causes:
  • Usage of the pool has reached 100%.
  • Something in the storage system is blocked.
  • The total capacity for the V-VOLs to be created exceeds the capacity for the estimated configurable V-VOL capacity.

    The estimated configurable V-VOL capacity can be confirmed by the following VSP One Block Administrator API and its attributes:

    GET <base URL>
    /simple/v1/objects/storage?
    withEstimatedConfigurableCapacities=true
    Attributes:
    • estimatedConfigurablePoolCapacity
    • estimatedConfigurableVolumeCapacity

    For more information about how to use VSP One Block Administrator API, see the REST API Reference Guide.

  • The capacity requirements for deduplication system data volume are not satisfied.

Solutions:

  • Add pool-VOLs to the pool.
  • Perform the task to reclaim zero pages to release pages in which zero data are stored.
  • Revise the setting of the subscription limit of the pool.
  • Delete V-VOLs that are not used.*
  • Change the settings to meet the requirements for the deduplication system data volume capacity. For more information, see the table of the maximum capacity of deduplication system data volumes (data store) in Deduplication system data volume specifications and requirements.
  • Contact customer support to solve the problem.
Cannot add a pool-VOL. Causes:
  • 1,024 pool-VOLs are already defined in the pool.
  • The pool-VOL does not fulfill the requirements for a pool-VOL.
  • Something in the storage system is blocked.

Solution:

A pool-VOL is blocked. SIM code 627xxx is reported. Causes:
  • A failure occurred in data drives greater than the DDP group redundancy. The redundancy of the DDP group depends on the number of the blocked PDEVs (data drives). For example:
    • When the DDP group configuration is 6D+2P and failures occur in three or more drives, the failures are considered to have occurred in data drives beyond the DDP group redundancy.

Solution:

  • Ask customer support to solve the problem.
A pool is blocked. Solution:
  • Ask customer support to solve the problem.
A pool cannot be restored. Causes:
  • Processing takes time because something in the storage system is blocked.
  • Usage of the pool has reached 100%.

Solutions:

  • Add some pool-VOLs to the pool to increase the capacity of the pool.
  • Perform the operation to reclaim zero pages to release pages in which zero data are stored.
  • Delete V-VOLs that are not used.*
  • Ask customer support to solve the problem.
A pool cannot be deleted. Causes:
  • The pool usage is not 0.
  • External volumes are removed from the pool before you delete the pool.
  • V-VOLs have not been deleted.

Solutions:

  • Confirm that the pool usage is 0 after the V-VOLs are deleted, and that you can delete the pool.
  • Ask customer support to solve the problem.
The LDEV that you used cannot be formatted after deleting the pool. Causes:

The pool is deleted or shrunk without restoring an error in the drive to which a DDP group belongs (while there is backup data in the spare area).

Solution:

Delete the DDP group to which the LDEV to be formatted belongs, retry the creation of the DDP group and the LDEV, and then retry the formatting of the target LDEV.

A failure occurs to the application for monitoring the volumes installed in a host. Causes:
  • Free space of the pool is insufficient.
  • Some areas in the storage system are blocked.

Solutions:

  • Check the free space of the pool and increase the capacity of the pool.
  • Perform the operation to reclaim zero pages to release pages in which zero data are stored.
  • Delete V-VOLs that are not used.*
  • Ask customer support to solve the problem.
When the host computer tries to access the port, an error occurs and the host cannot access the port. Causes:
  • Free space of the pool is insufficient.
  • Some areas in the storage system are blocked.

Solutions:

  • Check the free space of the pool and increase the capacity of the pool.
  • Reclaim zero pages in order to release pages in which zero data are stored.
  • Delete V-VOLs that are not used.*
  • Ask customer support to solve the problem.
DP-VOL capacity cannot be increased.

Causes:

  • The total capacity for the V-VOLs to be expanded exceeds the capacity for the estimated configurable V-VOL capacity.
  • To identify a cause, see Command Control Interface User and Reference Guide.

Solutions:

  • Verify whether the processing for increasing V-VOL capacity meets the conditions described in Requirements for increasing V-VOL capacity.
  • Retry the operation after 10 minutes or so.
  • Ask customer support to solve the problem.
Cannot reclaim zero pages in a V-VOL. Cause:
  • Zero pages in the V-VOL cannot be reclaimed because the V-VOL does not meet conditions for releasing pages in a V-VOL.

Solution:

The V-VOL cannot be released if the process to reclaim zero pages in the V-VOL is interrupted. Cause:
  • Pages of the V-VOL are not released because the process of reclaiming zero pages was interrupted.

Solution:

Cannot release the protect attribute of the DP-VOLs. SIM code 628000 was issued. Causes:
  • The pool is full.
  • The pool-VOL is blocked.
  • The pool-VOL that is an external volume is blocked.

Solutions:

  • Add pool-VOLs to the pool to increase the free space in the pool.
  • Perform the reclaiming zero pages task to release pages in which zero data are stored.
  • Delete DP-VOLs that are not used.*
  • Contact customer support to restore the pool-VOL.
  • If the blocked pool-VOL is an external volume, verify the status of the path blockade and the external storage system.
  • After performing above solutions, release the protect attribute (Data Retention Utility) of the DP-VOL.
SIM code 622xxx was issued. Cause:
  • Usage of the pool has reached 100%.

Solutions:

  • Add pool-VOLs to the pool to increase the free space in the pool.
  • Perform the task to reclaim zero pages in order to release pages in which zero data are stored.
  • Delete V-VOLs that are not used.* See V-VOL deletion.

The protect attribute of Data Retention Utility can have been set to V-VOLs. After performing the above solutions, release the protect attribute of the V-VOLs.

SIM code 624000 was issued. Cause:
  • The pools and V-VOLs configuration, of which the size is more than the supported capacity, is created.

Solutions:

  • Remove pools that are not used.
  • Delete V-VOLs that are not used.*
  • Remove Thin Image Advanced pairs that are not used.
  • Shrink pools capacities.
Formatted pool capacity displayed by the raidcom get pool command does not increase. Causes:
  • Another pool is being formatted.
  • The pool usage level reaches up to the threshold.
  • The pool is full.
  • The pool is blocked.
  • I/O loads to the storage system are high.
  • The cache memory is blocked.
  • Pool-VOLs are blocked.
  • Pool-VOLs that are external volumes are blocked.

Solutions:

  • Confirm the display again after waiting for a while.
  • Add pool-VOLs to the pool to increase the free space in the pool.
  • Perform the task to reclaim zero pages to release pages in which zero data are stored.
  • Confirm the display again after decreasing I/O loads of the storage system.
  • Delete V-VOLs that are not used.*
  • Contact customer support to restore the cache memory.
  • Contact customer support to restore the pool-VOL.
  • If the blocked pool-VOL is an external volume, confirm these situations:
    • Path blockage
    • Status of the storage system
The shrink pool operation ends abnormally. Causes:
  • Cache memory maintenance was performed while the shrink pool operation was in progress.
  • A cache memory error occurred while the shrink pool operation was in progress.
  • The I/O load to V-VOLs associated with the pool is too high.
  • V-VOLs associated with the pool are blocked.

Solutions:

  • Restore the cache memory, and then perform the shrink pool operation again.
  • Wait until the I/O load to V-VOLs associated with the pool is lower, and then perform the shrink pool operation again.
  • Delete or format V-VOLs associated with the pool, and then perform the shrink pool operation again.
When the capacity saving status of DRD-VOLs is Enabling, the initialization processing to enable the capacity saving setting is stopped. Cause:
  • An error occurs while the capacity saving status is changing, and then the processing aborts. After recovering from the error, the resumed status change process fails.

Solution:

  • Delete the target volume, and then retry the operation.
The capacity saving status of DRD-VOLs whose Deduplication Data status is Disabled fails. Causes:
  • The shared memory is volatilized and the storage system is restarted.
  • The pool is initialized.
  • The pool volumes are formatted.
  • The processing for deleting the DRD-VOL failed.

Solution:

  • Format the operation target DRD-VOLs.
A capacity saving status with DRD-VOLs whose Deduplication Data status is Enabled fails. Causes:
  • The shared memory is volatilized and the storage system is restarted.
  • The pool is initialized.
  • The pool volumes are formatted.
  • The processing for deleting the DRD-VOL failed.

Solution:

  1. In the pool, back up all of the DRD-VOLs with deduplication data enabled.

    Note: During the backup, SIM code 680001 might be reported and the data might not be read. In this case, back up only the data that can be read. Even if the SIM code 680001 is reported, perform this operation.

  2. Block DRD-VOLs in this order: 1. All DRD-VOLs with deduplication data enabled. 2. All deduplication system data volumes.
  3. Run the raidcom initialize pool command by specifying a pool containing the deduplication system data volumes.
  4. Format these LDEVs: Deduplication system data volumes (data store) and DRD-VOLs with deduplication data enabled.

    Caution: Do not try to restore the LDEVs because these DRD-VOLs cannot be used again.

  5. Verify the compression accelerator settings for the DRD-VOLs with deduplication data enabled (with deduplication and compression enabled) in the pool initialized in step 3, and for the deduplication system data volumes (data store) in the pool.
  6. Restore the backup data, or try to delete the LDEVs again.

Note: If you format DRD-VOLs for which deduplication data is disabled, the capacity saving for the DRD-VOLs might become compression. If you initialize duplicated data for a pool that has DRD-VOLs for which deduplication data is enabled, the capacity saving for the DRD-VOLs might become deduplication and compression. Therefore, verify the capacity saving of DRD-VOLs after formatting is complete.

When a DRD-VOL with capacity saving enabled is removed, one of these problems occurs:
  1. The capacity saving status of the DRD-VOL is Deleting Volume, and the progress indicates a hyphen (-).
  2. The capacity saving status of the DRD-VOL is Disabled.
If the DRD-VOL meets either condition 1 or 2, retry the DRD-VOL deletion.
The capacity saving status of a DRD-VOL is Deleting Volumes, however the processing progress does not increase. Causes:
  • The pool used capacity exceeded the depletion threshold.
  • The pool with which the target DRD-VOL is associated is blocked, or the pool volumes are blocked.
  • The deduplication system data volume of the pool with which the target DRD-VOL is associated is blocked.

Solutions:

If the pool used capacity exceeded the depletion threshold, take these actions:

  • Verify the free capacity of the pool, and then expand the pool capacity for the capacity shortage.
  • Release pages in DRD-VOLs to reclaim zero pages.
  • Delete DRD-VOLs that are not used.*

If the pool with which the target DRD-VOL is associated is blocked, or if the pool volumes are blocked, take this action:

  • Restore the pool or pool volumes.
The saved capacity for the DRD-VOL whose capacity saving is enabled is not increased. Causes:

If the saved capacity is not increased, the initial capacity saving processing might have been stopped. The initial capacity saving processing is performed on the existed data in DRD-VOLs. These are causes for stopping the initial capacity saving processing:

  1. The cache write pending rate of the MP unit for the DRD-VOLs is 50% or more.
  2. The controller of the storage system is blocked.
  3. The ratio of a free pool space with which the DRD-VOLs are associated is 1% or less.
  4. The size of a free pool space with which the DRD-VOLs are associated is 120GB or less.
  5. The pool with which the DRD-VOLs are associated is shrunk.
  6. The pool volumes are blocked.
  7. The operation targeted DRD-VOLs whose capacity saving is enabled are blocked.
  8. The used capacity rate of the data store area for the operation targeted DRD-VOLs enabled of the capacity saving is 80% or more.
  9. The average operating ratio for MPs on the basis of a controller is 70% or more.

Solutions:

  • For item number 1, reduce the written data size from hosts.
  • For item number 2, restore the blocked controller.
  • For item number 3 and 4, expand the pool capacity.
  • For item number 5, wait until the pool shrink task is completed.
  • For item number 6, restore the blocked pool volumes.
  • For item number 7, restore the blocked DRD-VOLs of the operation target.
  • For item number 8, split the operation targeted DRD-VOLs into DRD-VOLs whose capacity saving is enabled and whose size is 2.4TB or less.
  • For item number 9, the storage system reduces the number of processes of the initial capacity saving. If you want to increase the amount of the processing, balance the loading on the basis of a controller.
The garbage data of DRD-VOLs for which capacity saving is enabled is increasing. Causes:

If the garbage data continues to increase, these are the potential causes. However, the garbage data is included in the system data:

  • The amount of written data by hosts (the average performance of host writing) exceeds the throughput of the garbage collection (the garbage collection performance).
  • The processing of the garbage collection is stopped.

Solutions:

Perform these actions if the amount of written data by hosts (the average performance of host writing) exceeds the throughput of the garbage collection (the garbage collection performance):

  • If the amount of written data by hosts exceeds the throughput of the garbage collection on a basis of a storage system, perform one of these actions:
    • Reduce the amount of written data by hosts.
    • Verify the design of pools and DRD-VOLs again.
  • If the amount of written data of hosts exceeds the throughput of the garbage collection on a basis of a MP unit, perform this action:

    To rebalance the load (the writing I/Os from hosts) to MP units, change the assignment of MP units.

  • If the amount of written data by hosts exceeds the throughput of the garbage collection on a basis of a DRD-VOL, perform this action:

    To rebalance the load (the writing I/Os from hosts) to DRD-VOLs, divide DRD-VOLs.

If the processing of the garbage collection is stopped, here are the possible causes:

  1. The cache write pending rate of the MP unit is 83% or more.
  2. There is no free space in the pool with which DRD-VOLs are associated.
  3. Pool volumes are blocked.
  4. DRD-VOLs of that the capacity saving function is enabled are blocked.

Solutions:

  • For item number 1, reduce the amount of written data by hosts.
  • For item number 2, expand the pool capacity.
  • For item number 3, restore the blocked pool volumes.
  • For item number 4, restore the blocked DRD-VOLs.
The actual performance for DRD-VOLs with capacity saving is lower than the estimate. Causes:
  • The setting is not correct.
  • The pool used capacity exceeds the threshold.
  • The DRD-VOLs are used in a task which is not suited with using of the capacity saving function.

Solutions:

  1. Verify the setting. If the setting is correct, go to step 2. If the capacity saving mode is accidentally set to Inline, change the mode to Post process. For the capacity saving mode, see the command, raidcom modify ldev -capacity_saving_mode in the Command Control Interface Command Reference.
  2. Verify whether the pool used capacity exceeds the warning threshold by looking at Pool Usage. If the pool used capacity has not exceeded the warning threshold, go to step 3.

    If the pool usage has exceeded the warning threshold, verify the garbage data size by looking at System Data.

    If the ratio of system data size in the data capacity before capacity saving is more than 10%, the pool usage will go below the warning threshold by the garbage collection. The ratio of the used capacity before saving goes below the warning threshold ratio so that the I/O performance will be improved. If you know that the performance decrement is temporary and you can wait until the recovery time, waiting is the workable alternative. However, if you do not have time to wait until the recovery, expand the pool capacity.

    If the ratio of the system data for the data capacity before capacity saving is less than 10%, expand the pool capacity.

  3. If the performance of DRD-VOLs is short even though there is no effect of the garbage collection, it is best practice not to use the capacity saving function for those volumes. However, this problem might be caused by overload due to the copy processing in a replication program product. In this case, the copy threshold option might improve the performance. This option has a side effect, and therefore determine whether to apply this option by referring to Copy threshold.
Creating DRD-VOLs with a capacity saving setting of Deduplication and Compression was performed. No DRD-VOLs were created but deduplication system data volumes were created. Cause:
  • After deduplication system data volumes are created, an error occurs while DRD-VOLs are created, and then the processing stops.

Solution:

  • Resolve the cause of the error. Then, re-create DRD-VOLs whose capacity saving is Deduplication and Compression.
The capacity saving was changed from Disabled to Deduplication and Compression for DRD-VOLs. However, the setting of DRD-VOLs is not changed, and deduplication system data volumes are created. Cause:
  • After deduplication system data volumes are created, an error occurs while the settings for DRD-VOLs are changed, and then the processing stops.

Solution:

  • Resolve the causes of the error. Then, change the capacity saving setting for DRD-VOLs again.
The capacity saving setting was changed to Disabled. However, deduplication system data volumes were not deleted. Cause:
  • An error occurs while deduplication system data volumes are deleted, and then the processing stops.

Solution:

  • Resolve the cause of the error. Then, delete deduplication system data volumes using the CCI command, raidcom modify pool -pool -delete dsd_volumes.
In a pool where there is no DRD-VOL with Deduplication and Compression enabled, a new DRD-VOL whose capacity saving setting is Deduplication and Compression cannot be created.
  • Cause: The number of pools to which DRD-VOLs with Deduplication and Compression enabled belong has reached the maximum number of pools containing DRD-VOLs with Deduplication and Compression enabled.

    Solution: For more information about the maximum number of pools, see Pool specifications and requirements.

  • Cause: The total capacity of created DRD-VOLs exceeds the estimated configurable capacity of V-VOL capacity.

    Solution: Add shared memory, and then retry the operation. Alternatively, delete the DRD-VOLs that are not used.

  • Cause: This problem is caused due to the same causes as those for the "Cannot create a DRD-VOL" problem listed in this table.

    Solution: Take actions by referring to the causes and the solutions for the "Cannot create a DRD-VOL" problem in this table.

In a pool where there is no DRD-VOL with Deduplication and Compression enabled, the capacity saving setting for DRD-VOLs cannot be changed from Compression to Deduplication and Compression.
  • Cause: The number of pools to which DRD-VOLs with Deduplication and Compression enabled belong has reached the maximum number of pools containing DRD-VOLs with Deduplication and Compression enabled.

    Solution: For more information about the maximum number of pools, see Pool specifications and requirements.

  • Cause: The total capacity of created DRD-VOLs exceeds the estimated configurable capacity of V-VOL capacity.

    Solution: Add shared memory, and then retry the operation. Alternatively, delete the DRD-VOLs that are not used.

  • Cause: This problem is caused due to the same causes as those for the "Cannot create a DRD-VOL" problem listed in this table.

    Solution: Take actions by referring to the causes and the solutions for the "Cannot create a DRD-VOL" problem in this table.

The capacity saving status of a DRD-VOL is Converting, however no progress is being made.
  • Cause: The used capacity of the pool containing the target DRD-VOL exceeds the depletion threshold. The free capacity percentage of the pool is 1% or less, or the free capacity of the pool is 120 GB or less.

    Solutions:

    • Verify the free capacity of the pool, and then expand the pool capacity for the capacity shortage.
    • Release pages to reclaim zero pages. For more information, see Zero pages reclaiming.
    • Delete a DRD-VOL that is not used. For more information, see V-VOL deletion
  • Cause: The target DRD-VOL is blocked.

    Solution: Restore the blocked DRD-VOL.

  • Cause: The pool containing the target DRD-VOL is blocked, or a pool volume is blocked.

    Solution: Restore the blocked pool or pool volume.

  • Cause: The deduplication system data volume in the pool containing the target DRD-VOL is blocked.

    Solution: Restore the blocked pool or deduplication system data volume.

  • Cause: The pool containing the target DRD-VOL is being shrunk.

    Solution: Wait for the pool shrinking operation to complete.

  • Cause: The cache write-pending rate for the MP unit is 30% or more.

    Solution: Reduce the amount of data written from the host.

  • Cause: The controller is blocked.

    Solution: Restore the blocked controller.

* If you delete DRD-VOLs for which the capacity saving setting is compression only or duplication and compression, the deletion processing might increase the pool usage.