IBM E16RMLL-I - Tivoli Storage Manager, Руководство по внедрению

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Chapter 5. Database and recovery log
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recovery log. Changes made to the database since the last backup cannot be
recovered if the database is lost. Database backups can only be used to
perform point-in-time recovery (that is, to the time of the last database
backup). In NORMAL log mode, you need less space for the recovery log,
since Tivoli Storage Manager deletes transactions once they have been
committed to the database.
򐂰
ROLLFORWARD
In rollforward mode, Tivoli Storage Manager caches all transaction changes
made to the database since the last time it was backed up. Tivoli Storage
Manager deletes cached transactions only after a successful database
backup. The cached transactions can be used to restore the database to its
most current state (roll-forward recovery) after loading the most current
database backup series. A database backup series created in
ROLLFORWARD mode can be used for either point-in-time recovery or
roll-forward recovery. We recommend ROLLFORWARD mode for the
superior recoverability it brings to the server database. Note that in
ROLLFORWARD mode, more recovery log space is required.
When you change the log mode to ROLLFORWARD, if the database backup
trigger is set, a database backup will immediately run.
To configure the log for ROLLFORWARD mode, issue the set logmode command,
as shown in Example 5-5. The command takes effect immediately. You do not
need to restart the server.
Example 5-5 Set logmode to roll forward
tsm: LOCHNESS_SERVER1>
set logmode rollforward
ANR2294I Log mode set to ROLLFORWARD.
To check that the command was successful, use the
query status
command and
note the Log Mode field.
Example 5-6 Check status for log mode
tsm: LOCHNESS_SERVER1>
query status
Server Name: LOCHNESS_SERVER1
Server host name or IP address: 9.43.86.84
...
Retry Period: 5 Minute(s)
Scheduling Modes: Any
Log Mode: RollForward
Database Backup Trigger: Not Defined
BufPoolSize: 261,120 K
...