We are using V9.01 service pack 4. Our media pools fail to move media from the save to scratch and media disappears. Jobs then fail to use available correct media and use blank tapes.
Below are my understanding of how the product works and how we are configured, but despite this media still disappears from media pools with no explaination.
We are using SQL 2000 database which is around 4gb in size.
We moved from a VLDB because every three months the database would completely corrupt and the maintenance utilities did not complete within 48 hours.
When media is erased it is removed from its media pool.
BABS uses a default GFS scheme containing 4 daily, 5 weekly and 12 monthly media. We use 4 daily, 4, weekly and 12 monthly media. This means that when a new media pool is created or an existing media pool returned to defaults then the minimum retention period must be adjusted using the following calculation:-
“(# of weekly media X 7)-1”
We do set the minimum number of media to 0 and the prune retension time to 0.
The database stores the media serial number and the BABS media label with each Job record in the database. Once a tape has been overwritten and the media for a job record no longer exists BABS automatically removes the media from the job record and the job detail.
BABS performs media maintenance when it starts each backup job. Therefore before a job runs it will move media in the Save set to the scratch set that exceeds the minimum retention time. It is not clear which date from the media record it uses. There are fields for Time of First Format, Last Format, Last Write, Last Read and expiration date. The last format and last read are the near to the start time of the backup job and the last write time are near to the time the backup job finishes.
BABS will always use media in the following order, Media in the Scratch set (using the oldest tape based on the last format date), then blank media and lastly any other media not in the Media pools. This means that if media has been removed from or is not listed in the media pool for any reason then it must be erased first.
Below are my understanding of how the product works and how we are configured, but despite this media still disappears from media pools with no explaination.
We are using SQL 2000 database which is around 4gb in size.
We moved from a VLDB because every three months the database would completely corrupt and the maintenance utilities did not complete within 48 hours.
When media is erased it is removed from its media pool.
BABS uses a default GFS scheme containing 4 daily, 5 weekly and 12 monthly media. We use 4 daily, 4, weekly and 12 monthly media. This means that when a new media pool is created or an existing media pool returned to defaults then the minimum retention period must be adjusted using the following calculation:-
“(# of weekly media X 7)-1”
We do set the minimum number of media to 0 and the prune retension time to 0.
The database stores the media serial number and the BABS media label with each Job record in the database. Once a tape has been overwritten and the media for a job record no longer exists BABS automatically removes the media from the job record and the job detail.
BABS performs media maintenance when it starts each backup job. Therefore before a job runs it will move media in the Save set to the scratch set that exceeds the minimum retention time. It is not clear which date from the media record it uses. There are fields for Time of First Format, Last Format, Last Write, Last Read and expiration date. The last format and last read are the near to the start time of the backup job and the last write time are near to the time the backup job finishes.
BABS will always use media in the following order, Media in the Scratch set (using the oldest tape based on the last format date), then blank media and lastly any other media not in the Media pools. This means that if media has been removed from or is not listed in the media pool for any reason then it must be erased first.
