Optimizing restore operations for clients

Standard IBM Spectrum® Protect progressive incremental backup operations are optimized to restore individual files or small numbers of files.

Progressive incremental backup minimizes tape usage, reduces network traffic during backup operations, and eliminates the storage and tracking of multiple copies of the same data. Progressive incremental backup might reduce the impact to client applications during backup. For a balanced level of backup and restore performance, try running progressive incremental backup with collocation set on, in the storage pool.

If restore performance is more important than a balance between backup and restore operations, you can optimize based on your goals for restore performance. When you optimize for restore operations, there are often costs in tape usage and backup performance.

When you optimize restore operations, the performance depends on the type of media that you use. For more information about the media that you can use to restore data, see Table 1.

Table 1. Advantages and disadvantages of the different device types for restore operations
Device type	Advantages	Disadvantages
Random access disk	Quick access to files No mount point needed	No reclamation of unused space in aggregates No deduplication of data
Sequential access disk (FILE)	Reclamation of unused space in aggregates Quick access to files (disk based) Allows deduplication of data	Requires mount point but not as severe an impact as real tape
Virtual tape library	Quick access to files because of disk-based media Existing applications that were written for real tape do not have to be rewritten	Requires mount point but not as severe an impact as real tape No deduplication of data
Active data pools	No sorting through inactive files to get to active data Can be defined on any type of storage pool Tapes can be taken offsite for disaster recovery	Cannot be used with random access disk pools
Tape	A large amount of data can be stored on a tape Tapes can be taken offsite for disaster recovery	Requires mount point and physical tape mounting/dismounting No deduplication of data Slower access to files because of sequential access of tapes

The following tasks can help you balance the costs against the need for optimized restore operations:

Identify systems that are most critical to your business. Consider where your most important data is, what is most critical to restore, and what needs the fastest restore. Identify which systems and applications you want to focus on, optimizing for restore.
Identify your goals and order the goals by priority. The following list has some goals to consider:
- Disaster recovery or recovery from hardware crashes, requiring file system restores
- Recovery from loss or deletion of individual files or groups of files
- Recovery for database applications (specific to the API)
- Point-in-time recovery of groups of files

The importance of each goal can vary for the different client systems that you identified as being most critical.

For more information about restore operations for clients, see Concepts for client restore operations.