Standard IBM® Tivoli® Storage Manager 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. Reference Table 1 for information about the media
that you can use to restore data.
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.