The following is an excerpt from Chapter 8 of Redbook "IBM Tivoli Storage Manager and DRM" (p. 197):
8. Now, specify the number of days before expiration is used to expire a
database backup series, using the SET DRMDBBACKUPEXPIREDAYS command.
defines criteria for DB backup series expiration. The value applies to both a
snapshot and a full plus incremental database backup series. The age of the
last volume in the series must exceed the expiration value defined here to be
eligible for expiration. The most recent backup series of either type is never
deleted. In Example 8-11, we specify an expiration value of 14 days. To
ensure that the database can be restored to an earlier level and database
references to files in the storage pool are still valid, the number of days
specified by this command and the number of days specified by the
REUSEDELAY parameter in the copy storage pool definitions should be the
same for the copy storage pools managed by DRM.
Example 8-11 Set the database backup series expiration value
tsm: RADON_SERVER1>set drmdbbackupexpiredays 14
ANR6700I SET DRMDBBACKUPEXPIREDAYS command completed successfully.
~~~
My question is why? Why would you want to keep so many copies of the DB? Only the most recent copy knows what tapes are in the vault, in what copypools, etc.. What good does a DB backup from 14 days ago do? Wouldn't it be okay to have REUSEDELAY for the copypool set to 14 days while having DRMDBBACKUPEXPIREDAYS set to something lower, like 1 or even 0?
Thanks for any input that anyone can provide.
8. Now, specify the number of days before expiration is used to expire a
database backup series, using the SET DRMDBBACKUPEXPIREDAYS command.
defines criteria for DB backup series expiration. The value applies to both a
snapshot and a full plus incremental database backup series. The age of the
last volume in the series must exceed the expiration value defined here to be
eligible for expiration. The most recent backup series of either type is never
deleted. In Example 8-11, we specify an expiration value of 14 days. To
ensure that the database can be restored to an earlier level and database
references to files in the storage pool are still valid, the number of days
specified by this command and the number of days specified by the
REUSEDELAY parameter in the copy storage pool definitions should be the
same for the copy storage pools managed by DRM.
Example 8-11 Set the database backup series expiration value
tsm: RADON_SERVER1>set drmdbbackupexpiredays 14
ANR6700I SET DRMDBBACKUPEXPIREDAYS command completed successfully.
~~~
My question is why? Why would you want to keep so many copies of the DB? Only the most recent copy knows what tapes are in the vault, in what copypools, etc.. What good does a DB backup from 14 days ago do? Wouldn't it be okay to have REUSEDELAY for the copypool set to 14 days while having DRMDBBACKUPEXPIREDAYS set to something lower, like 1 or even 0?
Thanks for any input that anyone can provide.