Best Practices - Sybase iDataAgent

Creating Subclients

As a best practice, it is recommended that you create separate subclients to backup data that undergo frequent changes.

For example, if the EXAMPLE and USERS dbspaces undergo frequent changes, you can create a separate subclient for each tablespace.

Example:

• User-defined subclient: Test1

   Content: EXAMPLE

• User-defined subclient: Test2

  Content: USERS

It is recommended that you create a separate user-defined subclient for the log files on the client.

Distributing the client data using subclients as recommended above, can help improve backup performance by organizing the workload on the client into logical groupings.

Subclient Content

As a best practice, it is recommended that you add only a few small databases to each subclient and add larger databases into separate subclients. On a restart condition, the system will back up all databases in the subclient from the beginning. For this reason, you would not want a large database that has completed its backup successfully to be backed up again only because a smaller one has caused a restart to occur.

Re-configuring Default Subclient Content

We recommend that you do not re-configure the content of a default subclient because this would disable its capability to serve as a catch-all entity for client data. As a result, some data will not get backed up or scanned.

Changing Storage Policies

If you change a storage policy for a default subclient, and want to restore to a point in time prior to the change (i.e., restore from previous storage policy), perform a Full backup of the database as soon as possible. Data from the old storage policy will not be considered as the most recent cycle and when it exceeds its retention period, and hence will be pruned.

Improving the Backup and Restore Performance

You can use the dbBlockSize registry key to improve the performance of your backup and restores. The Sybase device blocksize parameter specifies the number of bytes per I/O operation for a dump device. By default, the block size is not specified in the dump command and will use the Sybase server's default block size. Use dbBlockSize registry key to override the default block size for a particular dump device. The block size must be at least one database page (2048 bytes) and must be an exact multiple of the database page size. For optimal performance, specify the blocksize as a power of 2. Example: 8192 (8k), 16384 (16k), or 32768 (32k).

Improving the Deduplication Performance

Use the following configuration for Sybase iDataAgent to obtain a better deduplication performance.

Use dbBlockSize registry key

The Sybase device blocksize parameter specifies the number of bytes per I/O operation for a dump device. By default, the block size is not specified in the dump command and will use the Sybase server's default block size. Use dbBlockSize registry key to override the default block size for a particular dump device. The block size must be at least one database page (2048 bytes) and must be an exact multiple of the database page size. For optimal performance, specify the blocksize as a power of 2. Example: 8192 (8k), 16384 (16k), or 32768 (32k).

Compression Settings

Turn off deduplication compression from subclient and storage policy copy level. See Setting Up Data Compression for step-by-step instructions.

Storage Policy Configuration

Use Non-deduplicated Storage Policy with Compression set as ON to backup the Sybase Logs (Incremental backup).