Comparing options for copying directory-container storage pool data to tape
In addition to replication, IBM Storage Protect provides options for copying data in a directory-container storage pool on disk to tape volumes for disaster recovery. Find the option that best meets your business requirements.
Review the following options:
Restrictions:
- 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.
- Replicate and protect data to a target replication server
- You can use the REPLICATE NODE command to replicate data between two IBM Storage Protect servers. Replication incrementally copies data from a source replication server to a target replication server to provide failover and failback capability. Along with replication, you can use the PROTECT STGPOOL command to protect the storage pool, which improves the efficiency of the replication process and allows you to repair damage in the storage pool by using the REPAIR STGPOOL command. This option might result in additional costs because two IBM Storage Protect servers must be maintained. For information, see Replicating client data to another server and Protecting data in directory-container storage pools.
- Create a deduplicated tape copy
- You can use the PROTECT STGPOOL command and specify the TYPE=LOCAL parameter value to copy deduplicated data in a directory-container storage pool to a container-copy storage pool on tape volumes. For information, see Copying deduplicated data in directory-container storage pools to tape.
- Create a hydrated tape copy
- A hydrated copy is a complete replica of a data object. The data object is copied without
compression or deduplication. Note: Depending on the device class and tape settings that are used, data might be compressed when it is written to tape.You can use copy storage rules to automatically copy hydrated data in a directory-container storage pool to tape volumes. For information, see Copying hydrated data to tape storage for disaster recovery.
Tape storage can be a cost-effective alternative to replication for copying your data. IBM Storage Protect provides options to create either a hydrated copy or a deduplicated copy of data in a directory-container storage pool and store the copy on tape. Table 1 compares the options for copying data to tape.
| Feature | Create a hydrated tape copy by using copy storage rules | Create a deduplicated tape copy by using the PROTECT STGPOOL command and specifying TYPE=LOCAL |
|---|---|---|
| Data protection | This option creates a hydrated copy of container storage pool data on tape. If a tape volume becomes damaged, only the damaged data is lost. You can still use the tape volume to restore undamaged data to the client nodes. |
This option creates a deduplicated copy of directory-container storage pool data on
tape. If a tape volume becomes damaged, the damage affects the entire storage pool. You cannot use the damaged tape volumes to repair your container storage pool. |
| Disaster recovery | If a disaster occurs, you can restore data to clients directly from the tape volumes. Because the tape volumes store hydrated data, you don't have to repair the container storage pool before you begin restoring data to clients. | If a disaster occurs, you must repair the directory-container storage pool by using the tape
volumes before you can begin restoring data to clients. This procedure can take several days or
longer. Tip: To promote faster restoration of data to clients after a disaster, consider
using copy storage rules to create a hydrated copy of your directory-container storage pool on tape
volumes instead.
|
| Repair source container storage pool | To repair minor damage to a file in a source directory-container storage pool, you must
restore the damaged file directly to the client by using the hydrated copy on tape. Then, back up
the file to the source directory-container storage pool to replace the damaged version. Warning: If the files that you restore are inactive files, carefully consider whether you want
to back them up to the container storage pool. Every time IBM
Storage Protect backs up your files, it marks the most recent
backup version as the active version.
|
To repair minor damage to data extents in a source directory-container storage pool, you can use the REPAIR STGPOOL command to repair the damaged data by using deduplicated data in a container-copy storage pool on tape volumes. |
| Blueprint size | Small, medium, or large Blueprints | Small or medium Blueprints |
| Storage pool type | Directory-container storage pool or on-premises cloud-container storage pool | Directory-container storage pool |
| Reclamation performance | Reclamation performance is typically better. Reclamation processing for hydrated data requires fewer database queries and updates because the server reclaims entire files instead of selectively reclaiming data extents. The tradeoff is that the server must recopy entire files, which might affect performance if the files are large. | Reclamation performance is typically slower. Multiple reclamation operations and database updates are required to process deduplicated data in container-copy storage pools on tape volumes. |
| Tape volume requirements | More tape volumes are required to copy hydrated data. | Fewer tape volumes are required to copy deduplicated data. |