Defining a tiering rule

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You can define a storage rule to implement tiering, which moves data from a directory-container storage pool on disk to cloud, tape, or file storage. When the storage rule is active, eligible data is tiered daily.

Before you begin

  1. Consider whether tiering is appropriate, given your storage environment and business goals. For instructions, see Determining whether tiering is appropriate for your storage environment.
  2. Review the following restrictions:
    • A tiering rule defines when data is tiered from one or more directory-container storage pools to cloud, tape, or file storage. The source and target storage pools must exist before you create the tiering rule.
    • For cloud tiering, the target must be a cloud-container storage pool on a Microsoft Azure cloud computing system or on a cloud computing system that uses the Simple Storage Service (S3) protocol, such as IBM Cloud® Object Storage or Amazon Web Services (AWS) S3. For the latest information about cloud object storage services that are supported, see technote 2000915.
    • You cannot use a stgrule to tier or copy data from IBM Storage Protect Plus to tape. To store IBM Storage Protect Plus data on tape, copy the data to an IBM Storage Protect server for storage on physical tape media or in a virtual tape library. For instructions, see Configuring operations for copying data from S3 client to tape.
    • You can tier data from IBM Storage Protect Plus to cloud-container storage pools, but only to cloud storage classes that support the rapid recall of data. For example, if you are using Amazon Web Services (AWS) with the Simple Storage Service (S3) protocol, do not move the data to Amazon S3 Glacier.
    • For tape tiering, the target storage pool must be defined for a physical or virtual tape library.
    • If data was protected to a directory-container storage pool by using the PROTECT STGPOOL command or by enabling storage pool protection in the Operations Center, the protected data cannot be tiered to cloud or tape storage. The protected data remains in the directory-container storage pool on the target replication server to help ensure data availability for restore and recovery operations.
      Tip: To determine how much data is retained in the directory-container storage pool for restore and recovery operations, issue the QUERY STGPOOL command with the FORMAT=DETAILED parameter setting. In the command output, the Space Used for Protected Data field specifies the amount of data that cannot be tiered because of protection requirements. You can remove the storage pool protection by using the REMOVE STGPROTECTION command. However, if you subsequently replicate data, and that data is then damaged or missing on the source replication server, you will not be able to recover that data from the target replication server by using the REPAIR STGPOOL command.
      This restriction does not apply to replication storage rules. When you replicate data by using replication storage rules, the data is eligible for tiering from the target replication server to cloud or tape storage.
    • For file tiering, the target storage pool must be a sequential-access storage pool with a device type of FILE. The storage pool is on disk.
    • File tiering is intended for data that might have to be frequently accessed. When data is tiered to file, any compression or deduplication is reversed to store a hydrated version of the data. Hydration helps to support faster data retrieval. To maintain the data in a hydrated state, do not enable data deduplication on the file storage pool.
    • If you use copy storage rules and tiering rules to copy and tier data from the same node, file space, and source container storage pool, data is tiered after copy operations are completed. When a tiering rule runs, the server skips any files that are not copied, and data is tiered the next time that the tiering rule runs. If more than one copy storage rule is defined to copy data for a node and file space, all copy operations must be completed before the tiering operation begins.
      Tip: To help maintain the currency of data in the target storage pool, you can run the BACKUP STGPOOL command as described in step 6.
      For more information about using copy and tiering rules for data on the same node, file space, and source container storage pool, see Managing copy and tiering storage rules.
  3. To optimize tiering, consider using this strategy:
    1. Create a tiering rule. By default, the newly created rule is inactive.
    2. Create a subrule to tier data from a single client. To select the best option for tiering data from the client, see Determining whether tiering is appropriate for your storage environment.
    3. Modify the parent tiering rule to make it active. The parent rule and its subrule will run daily.
    4. Verify the tiering results. If necessary, update the subrule to add more clients or create additional subrules.
    Tip: To view an example of how to set up tiering, see Tiering scenario: A step-by-step example.
  4. Before you tier data to cloud storage, configure replication to create a backup copy of the data in the directory-container storage pool. The preferred method is to configure replication with the PROTECT STGPOOL command. For instructions, see Replicating client data to another server.
    Restriction: Data that is tiered to cloud storage is no longer protected by the PROTECT STGPOOL process.
  5. Before you tier data to tape storage, consider whether to enable collocation. Collocation can reduce the number of volumes that must be accessed when a large amount of data must be restored. You can enable collocation by specifying the COLLOCATE parameter on the DEFINE STGPOOL or UPDATE STGPOOL command.
  6. If you plan to apply a tiering rule and a copy storage rule to the same node, file space, and source container storage pool, consider scheduling regular backup operations to maintain the currency of data in the target storage pool.

    To schedule regular backup operations for a directory-container storage pool, use the BACKUP STGPOOL command. Specify the same target storage pool that is defined in the copy storage rule.

Procedure

To define a tiering rule, complete the following steps:

  1. On the Operations Center menu bar, click Storage > Storage Rules.
  2. On the Storage Rules page, click +Create Rule.
    Tip: To help ensure that active data can be quickly restored, select the option to tier only inactive data. By selecting this option, you ensure that active data remains on local disk storage, from which restore operations are typically faster.
  3. On the Create Rule page, complete the fields and click Create.
    Tip: Alternatively, you can define a storage rule by using the DEFINE STGRULE command. For more information, see DEFINE STGRULE (Define a storage rule for tiering).

Results

The storage rule is defined. By default, the storage rule is inactive. If you activate the storage rule, the rule runs on a daily schedule.
Tiering results differ, depending on whether the data is tiered to cloud, tape, or file storage:
Cloud storage
If data in a directory-container storage pool is compressed, encrypted, or both, the data is moved to the cloud-container storage pool in the same format. All extents that are required to rebuild a cloud object are copied to the tier, if the extents are not already there.
Tape storage
If data in a directory-container storage pool is compressed or deduplicated, and the data is tiered to tape, the data is no longer compressed or deduplicated. If data is encrypted on a client and tiered to tape, the data remains encrypted on tape. If data is encrypted by the IBM Storage Protect server and tiered to tape, the data is decrypted on tape.
File storage
If data in a directory-container storage pool is compressed, encrypted, or deduplicated, and the data is tiered to file, the data is no longer compressed, deduplicated, or encrypted. The only exception is the case when data is encrypted on a client. In that case, the data remains encrypted after tiering to file storage.

What to do next

Optionally, you can take the following actions:
  • To specify exceptions to the storage rule, define one or more subrules. For instructions about defining subrules, see Defining a tiering subrule.
  • When you are ready to activate the tiering rule, on the Properties tab, click Modify, click the Active toggle, and click Save. The active tiering rule and any subrules run daily at the scheduled time. (Alternatively, activate the storage rule by issuing the UPDATE STGRULE command with the ACTIVE=YES setting.)
  • To protect data that was tiered to tape, encrypt tape drives by following the instructions in Configuring tape drive encryption.
  • To ensure that data that was tiered to tape is backed up, set up a schedule to run the BACKUP STGPOOL command daily. For more information, see DEFINE SCHEDULE (Define a schedule for an administrative command).