Table of Contents
Advertisement
Whenever the system detects that the recovery log needs extra space, it triggers
the expansion and writes messages in the activity log, as shown in the query
actlog command in Example 5-11.
Example 5-11 Activity log messages from recovery log expansion
tsm: LOCHNESS_SERVER1>
...
02/16/06 18:06:48 ANR4413I Recovery Log Space expansion Is Needed, 4 Megabytes
needed.
02/16/06 18:06:48 ANR4412I Data Base and Recovery Log Space expansion
triggered.
02/16/06 18:06:50 ANR2260I Recovery log volume D:\TSMDATA\RLP\L8675309.LOG
defined.
Note: The maximum size of the recovery log is 13 GB. The server will not
automatically extend the recovery log beyond 12 GB. An automatic expansion
may exceed the specified database or recovery log maximum size, but not the
13 GB recovery log limit. However, after the maximum has been reached, no
further automatic expansions will occur.
Important: Although Tivoli Storage Manager can expand either the database,
recovery log, or both if needed, be careful if using software mirroring. You can
only specify one directory location for the expansionprefix parameter in the
define spacetrigger command. If you are using Tivoli Storage Manager
mirroring for the database or log, you may find volumes on a single disk,
making mirroring ineffective. You must reallocate the mirror copies to the
correct place.
5.6 Mirroring
When you first install Tivoli Storage Manager and initialize your server, the
database and recovery log volumes are not mirrored. However, we strongly
recommend that you create mirrors for the database and recovery log volumes.
Mirroring of database and recovery log volumes provides an extra level of
recoverability, should a system fail during a write operation. If a partial write to a
non-mirrored volume occurs, transaction recovery operations cannot complete
when the server is restarted. The database will need to be restored from its most
recent backup. With mirrored volumes, the chance that at least one of the mirror
writes was successful is much higher. If a partial write is detected, a mirror
volume can be used to construct valid images of the missing pages. For this
reason we recommend that you use the Tivoli Storage Manager provided
202
IBM Tivoli Storage Manager Implementation Guide
query actlog
Advertisement
Table of Contents
