Staging area guidance with different retention policies

[TwistNShout]

Hi,

We have an existing system, running Netbackup 7.5 on Solaris, without vaulting licences.

Currently we have a number of policies and schedules running, with different retention periods, that all run direct to tape. There are a number of different tape pools, that coincide with the different retention periods. These backups consist of Oracle and file backups. We are considering moving to disk staging using basic disks to possibly speed up the time to take the backups, and also hopefully speed up recovery (as the images will be available on disk rather than the library having to mount tape etc). But I could do with some guidance, I have the admin guides but it is more suggested best practice I could do with. Can anyone point me at white papers or guides please?

The schedules still define how long images are kept on tape but, given we have 2 year retention on some data, how do I define that the disk image can be deleted after a couple of weeks?

In order to work with multiple retention periods, do we have one disk_stage unit per retention period?

I'm looking at most stuff just staging through disk to tape, with no problem being deleted from disk once successfully written to tape. But 2 or 3 main databases we would want to keep last full backup plus the daily incrementals since that point on disk even though they have been written to tape.

Thanks in advance for any help

[Marianne · Accepted solution]

There is no way to specify different retentions with BasicDisk when staging is done.

There are only 2 factors that control the period that images will remain on disk:
1. Retention in the policy schedule
2. High water mark on BasicDisk STU

If High Water mark is reached before retention period has been reached, the oldest images that have duplicated to tape will be expired/deleted until low water mark is reached.

So, to ensure enough copies on disk are kept, you need to ensure sufficient disk space.

With Enterprise Disk license, you can configure Advanced Disk which can be used in Storage Lifecycle Policies.
The SLP allows you to specify different retentions for the backup to disk and duplicate copy on tape.

There are these TNs that explain how relocation and cleanup is done with Disk Staging:

Disk Staging Relocation Behavior: http://www.symantec.com/docs/TECH44719

Disk Staging Cleanup Behavior: http://www.symantec.com/docs/TECH66149

This White Paper is fairly old but still lots of useful info:
http://eval.symantec.com/mktginfo/enterprise/white_papers/b-whitepaper_nbu_disk_based_data_protectio...

Hope this helps.

[TwistNShout]

Thanks Marianne, just the sort of thing I needed :)

[Marianne]

Some more reading matter:

NetBackup 7.5 Best Practice - Using Storage Lifecycle Policies http://symantec.com/docs/HOWTO73205