I have just been gently nudged to provide a summary to my earlier question.
I appologize for not doing so earlier. I have no excuse (at least, not one
I would believe...)
I received excellent responses from:
Paul Rockwell at rockwell_at_rch.dec.com and
Adrian Ho at adrianho_at_nii.ncb.gov.sg
Both suggested relying on NSRs tape management facilities, rather
than adding an additional level of complexity.
I have included Paul's response and some further comments below:
Paul Rockwell at rockwell_at_rch.dec.com wrote:
>At 10:59 AM 2/28/96 -0800, you wrote:
>>We are just getting in to using NetWorker Save and Restore, and I
>>could use some advise on how to set up our tape rotation.
>>
>>What we are thinking of is initializing a tape for each day's backup
>>and have a rotation of 5 weeks.
>>
>>e.g. Bck.Mon.1
>> Bck.Tue.1
>>.
>>.
>>.
>> Bck.Sat.5
>> Bck.Sun.5
>You don't need to bother with this. It's not an efficient use of tape (or your
>time).
>NSR will keep track of what save set is on what tape, and prompt you for the
>right one. Just have enough tapes on hand to cover the 5 week rotation, then
>label them sequentially (you can use NSR's label templates).
After further examination, we decided that the added complexity involved
was not worth the (minimal) benefits we thought we would get.
We are labeling the tapes 'server.seq', just like Paul (and NSR) suggested.
>>We will have a browse and retention policy of one month, so each tape
>>should be marked for recycle next time its number comes up.
>>
>>This should all work from what I can tell, but...
>Maybe not. It depends on the backup schedule that you have set up for the
>clients.
>Remember that a volume will not be marked recyclable until all save sets on it
>become recyclable. That only happens when all save sets of a backup cycle
>(full and incrementals) pass the retention date.
>>We also want to take the last full backup of each month and retain it
>>for 1 year. When we get to that tapes backup day, we will label a new
>>tape appropriately (i.e. the same label as the tape that is being
>>retained). Even this seems legitimate.
>You'd be better off cloning those save sets onto a separately labeled tape
>pool, and taking those tapes off site. You then have a record of both tapes
>in NSR's media pool - and part of that information is a field that indicates
>media location.
Cloning requires two or more tape devices, so this is not really an option
here. What we are doing now is pulling the monthly backups out of the
rotation - marking the tapes as manually recycled in the Volume Management
screen and setting the correct offsite location.
When we need a new tape to replace the one sent offsite, we just pick the
next sequential tape label.
We will never have two tapes with the same label, so recovery is
strictly "by-the-book".
>>The problem is, what if we need to recover from the tape that has been
>>retained. Can we use scanner to reload the index from that tape given
>>that the database will already have a different tape with the same label
>>catalogued?
>By cloning the full backups into a separately labeled pool, you avoid
>this problem. Use scanner to repopulate the client index, then
>recover as usual. Just remember that you have to manually delete
>save sets that you scan in from the client indices...
>Alternatively, if you know what save set and where it is on the tape,
>you can use scanner to extract the save set, then use uasm to
>extract the file.
>--------
>+---------------------------+ Paul E. Rockwell
>| | | | | | | | Northeast Region SBU Technical Support
>| d | i | g | i | t | a | l | Digital Equipment Corporation
>| | | | | | | | 500 Enterprise Drive
>+---------------------------+ Rocky Hill, CT 06067 USA
> http://www.digital.com Internet: rockwell_at_rch.dec.com
> Telephone: (860) 258-5022
Dwayne Prysiazny DPrysiazny_at_Galaxy.Gov.BC.CA
(604)389-3066
Information Technology Services Division, Ministry of Finance,
4000 Seymour Place, Victoria, BC, V8X 4S8
Received on Fri Apr 26 1996 - 00:10:32 NZST