Appending Jobs to Tapes

[dwilson]

I am looking for general discussion/info on how Netbackup knows to append jobs to an already used media. What I am seeing in my environment is a Policy will run, but some jobs may fail inside that policy. The next morning I will go in and restart the job, but instead of Netbackup appending the restarted jobs to an already existing tape (has plenty of available space). It will pull another from Scratch pool and start to use it. This is not a huge ordeal as we have spares, but adds to our shelf size and does not let us run as effiecently as possible. Can someone share info on this process or maybe some links pertaining to this. I would like to correct this if possible.

[Mark_Solutions]

Generally NBU will keep writing to a tape until it is full

If it has a choice of tapes to use it will select the one used least and put it in the drive that has had the least amount of mounts

What it wont do, by default, is write different retentions to the same tape.

So if you have a tape that has been used for Daily backups with a 27 day retention and you re-run a Weekly backup with a 3 month retention it will have to use a different tape.

If you have only one tape drive you can make sure it only uses one tape at a time by setting the properties of the Volume Pool used (right click the volume pool and select Change) to have no more than one partially full tape available. - you can do similar number accoring to the number of drives you have.

Hope this helps

[dwilson]

Sorry forgot to add we are using a IBM robot, with 5 drives. The jobs in question are all in the same Policy, and all Retention/Volume Pool settings are the same.

[Will_Restore]

Maximum number of partially full media

(I see Mark has already mentioned this above)

[Marianne]

Do you have more than one media server and/or more than one Storage Unit?

Are you backing up to specific Storage Unit or STU Group (as per Policy config)? or Any Available?

[Rakesh_Khandelw]

NetBackup Admin Guide Vol 2 has all the information you are looking for, in great details. Look under Reference Topics, section "How NetBackup selects media"

6.5 Administrator's Guide for UNIX and Linux, Volume 2 (  http://www.symantec.com/docs/TECH52802 )

7.0 Administrator's Guide for UNIX,Linux, II  http://www.symantec.com/docs/TECH127080
7.1 NetBackup Administrator's Guide for UNIX and Linux, Volume II  http://www.symantec.com/docs/DOC3651
 

[dwilson]

Alright this will give me a starting point to work with. I will look over the documentation and see if I can figure it out.

Marianne to answer your questions, we have a single Master/Media server and 11 different Storage Unit. The one the policy is using one certain Storage Unit.