The database does not store client data; it points to
the locations of the client files in the storage pools. The Tivoli® Storage
Manager database
contains information about the Tivoli Storage
Manager server.
The database also contains information about the data that is managed
by the Tivoli Storage
Manager server.
The database includes information about:
- Client nodes and administrators
- Policies and schedules
- Server settings
- Locations of client files on server storage
- Server operations (for example, activity logs and event records)
- Intermediate results for queries
The maximum size of the Tivoli Storage
Manager database
is 4 TB.
The database can be distributed across up to 128 directories. It is important that
the database is placed on fast, reliable disks that are configured
for random access I/O. Locating each directory on a different file
system provides the best performance because the data is striped across
the directories. Enable read cache for the database, and enable write
cache if the disk subsystem supports it.
The database cannot be mirrored through Tivoli Storage
Manager, but it
can be mirrored by using hardware mirroring, such as Redundant Array
of Independent Disks (RAID) 5.
Attention: If the database is unusable, the
Tivoli Storage
Manager server is
unavailable. You must backup the database to ensure that data that
is managed by the server can be recovered. Encrypt sensitive data by
using the
Tivoli Storage
Manager client or a storage device, unless the storage media is
physically secured. Security can be compromised even if data is not
recovered. If a database is lost and cannot be recovered, it might
be difficult or impossible to recover data that is managed by that
server. Fragments of data or complete files might be read from storage
pool volumes that are not encrypted. See
Protecting the server for steps that you can take to protect your database.
The database manager manages database volumes, and there is no need to
format them. Some advantages of the database manager are:
- Automatic backups
- When the server is started for the first time, a full backup begins
automatically. When the server is next started, the database manager
automatically backs up the database according to the following values
set by Tivoli Storage
Manager:
- The active log space that is used since the last backup, which
triggers a full database backup
- The active log utilization ratio, which triggers an incremental
database backup
The database manager automatically backs up
the database when the archive log usage is 80% full.
- Automatic statistics collection
- Automatic statistics collection helps to improve database performance
by collecting up-to-date table statistics. The database manager determines
which statistics must be updated.
- Automatic database reorganization
- Reorganization of table data can be initiated by the server, or
by DB2®. If server-initiated
reorganization is enabled, based on table activity, the server analyzes
selected database tables and their indexes to determine when reorganization
is required. The database manager runs a reorganization while server
operations continue.
Attention: If reorganization by DB2 is enabled, DB2 controls the reorganization process. Reorganization
by DB2 is not recommended.
- Multiple data streams for database backup and restore
- Using a single data stream to back up databases of multiple terabytes
can take many hours. It can also affect the administrator’s ability
to schedule database backups effectively. The time to recover the
server by using a single data stream might not be enough to meet disaster
recovery objectives for the server. The Tivoli Storage
Manager server provides
a multiple data stream capability for backups and restores.
- SQL queries
- The database makes more sophisticated SQL queries on the data
possible. To take advantage of these functions, you must use SQL to
develop new tools and create SQL statements.
- Database audits
- Database audits are run automatically, as needed, to ensure consistency.
As data is added to the server database, the database manager checks
data constraints and data types. Online integrity checks can prevent
problems for which offline audits had been needed in earlier releases.