IBM E16RMLL-I Implementation Guide - Page 243

Estimate Dbreorgstats

Page 243 highlights

You should think of this as a security feature. Database backups are extremely important-you do not want to be in the situation where the last seven days of database backups are contained on one tape that, at the crucial moment when a restore is required, turns out to be unreadable. That is why you have to use a new tape each time you back up the database, regardless of whether it is a full or incremental backup. Use the delete volhistory command to remove the references to old database backups from the Tivoli Storage Manager database. Depending on the options chosen, delete volhistory can delete sequential volumes used for database backups, storage pools, or other purposes. When records containing volume history information about volumes that are not in storage pools (volume types DBSNAPSHOT, BACKUPFULL, BACKUPINCR, and EXPORT) are deleted, the volumes return to scratch status if they were acquired by Tivoli Storage Manager as scratch volumes. For scratch volumes with device type FILE, the files are deleted. When records containing volume history information about volumes in storage pools are deleted, the volumes themselves are not affected and remain in the Tivoli Storage Manager database. In 12.2.2, "Defining the volume history schedules" on page 380, we describe setting up a schedule to take care of volume history deletion automatically. Tip: Do not run the delete volhist command to delete obsolete database backups if you are using DRM. DRM handles the expiry itself. 5.9.2 ESTIMATE DBREORGSTATS Occasionally, if your database grows to be quite large, and has been in use for a long period of time, it may benefit from a reorganization. Although database dump and reload is beyond the scope of this book, a command introduced with Tivoli Storage Manager V5.3 might assist you in determining whether your database needs attention. The ESTimate DBREorgstats command examines the database and determines whether the database would benefit from a re-organization. Example 5-20 shows how to run the command. Example 5-20 Estimating database reorganization statistics tsm: LOCHNESS_SERVER1>estimate dbreorgstats wait=yes ANR0984I Process 87 for ESTIMATE DBREORG started in the FOREGROUND at 12:09:21. ANR1782W ESTIMATE DBREORG process 87 started - server performance may be degraded while this process is running. Chapter 5. Database and recovery log 213

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Chapter 5. Database and recovery log
213
You should think of this as a security feature. Database backups are extremely
important—you do not want to be in the situation where the last seven days of
database backups are contained on one tape that, at the crucial moment when a
restore is required, turns out to be unreadable. That is why you have to use a
new tape each time you back up the database, regardless of whether it is a full or
incremental backup.
Use the
delete volhistory
command to remove the references to old database
backups from the Tivoli Storage Manager database. Depending on the options
chosen,
delete volhistory
can delete sequential volumes used for database
backups, storage pools, or other purposes.
When records containing volume history information about volumes that are not
in storage pools (volume types DBSNAPSHOT, BACKUPFULL, BACKUPINCR,
and EXPORT) are deleted, the volumes return to scratch status if they were
acquired by Tivoli Storage Manager as scratch volumes. For scratch volumes
with device type FILE, the files are deleted.
When records containing volume history information about volumes in storage
pools are deleted, the volumes themselves are not affected and remain in the
Tivoli Storage Manager database. In 12.2.2, “Defining the volume history
schedules” on page 380, we describe setting up a schedule to take care of
volume history deletion automatically.
5.9.2
ESTIMATE DBREORGSTATS
Occasionally, if your database grows to be quite large, and has been in use for a
long period of time, it may benefit from a reorganization. Although database
dump and reload is beyond the scope of this book, a command introduced with
Tivoli Storage Manager V5.3 might assist you in determining whether your
database needs attention.
The
ESTimate DBREorgstats
command examines the database and determines
whether the database would benefit from a re-organization. Example 5-20 shows
how to run the command.
Example 5-20
Estimating database reorganization statistics
tsm: LOCHNESS_SERVER1>
estimate dbreorgstats wait=yes
ANR0984I Process 87 for ESTIMATE DBREORG started in the FOREGROUND at 12:09:21.
ANR1782W ESTIMATE DBREORG process 87 started - server performance may be
degraded while this process is running.
Tip:
Do not run the
delete volhist
command to delete obsolete database
backups if you are using DRM. DRM handles the expiry itself.