Best way to allow multiple jobs to write to the same tape

[Tim_Anderson_2]

Hi there,

We're having some problems getting our weekly full backups to run correctly.  Here's the scenario:  We have multiple jobs targeting different sources (Windows servers, NAS device, exchange, SQL, etc.) that run over the weekend.  The backup windows have been established such that each job is padded a little to allow for varying backup times, but they run in sequence and take about 10 hours for them all to complete.  The tapes are switched out and taken offsite each week, and we're not really too concerned with the automatic overwrite protection since each tape is used once over the weekend then not used for about 2 months.  We're using 400GB LTO3 tapes, and our total backup size is around 300GB, so the tape is pretty full after each backup

Now for the problem:  We want the first backup job to basically start "fresh" on each tape since there isn't enough room on the tape to append.  However, if we leave overwrite protection on, the first job writes completes then marks the tape as Overwrite Protected, which means that the subsequent jobs don't have any available media, so they sit there queued all weekend.

Here are what I see as our possible options with my questions in parens at the end:

1.  Manually move each tape over to scratch media after putting it in the drive.  This will make the first job in the chain start at the beginning of the tape and overwrite the old contents.  I would have to make each job use the "Append, then Overwrite" option.  (But, will this properly overwrite the 75% full tape from the beginning for the first job and allow subsequent jobs to append properly?)

2.  Run an erase job manually after putting it in the drive.  This will erase all the old contents of the tape and make the first job in the chain start at the beginning of the tape.  I would have to make each job use the "Append, then Overwrite" option.  I assume that this will this properly append the subsequent jobs since the tape has been erased.  (But is there any way to schedule this erase job so it doesn't have to be manually run each week?)

3.  Set the first job up to Overwrite no matter what, then each subsequent job to append. (Will this start from the beginning of the tape for the first job every time?)

4.  Consolidate all of the backup jobs into one huge job. (I'd rather NOT do this, since sometimes we need to do on-demand backups of certain areas, and also we get random communications errors sometimes so we have the problematic jobs set to retry on error so we can ensure a good backup...  If we had one job it'd have to backup EVERYTHING again if there was an error instead of just the problem area.)

I'm sure I'm missing some options, so maybe some of you gurus can give me some ideas, or tell me what the best way to handle this situation is.  If I forgot any necessary details, just post up the question and I'll respond as soon as I can.


Thanks for your help!
Aaron

[Ken_Putnam]

However, if we leave overwrite protection on, the first job writes completes then marks the tape as Overwrite Protected, which means that the subsequent jobs don't have any available media, so they sit there queued all weekend.


You need to set all  jobs to use the same media set (Weekly Full, for example)

the media set properties should be  APP of 10 hours, and OPP of however long you want to keep each weekly.  if you want to keep then for 6 seeks, make the OPP 41 days

Then set the first job of the night to Overwrite, and all the rest to APPEND and you should be good to go

This will indeed start at the beginning of the tape, and since you have separate jobs rather than multiple steps, if one job has problems, the whole job is not marked as failed, only the one job.

[Tim_Anderson_2]

So the only problem I see with that is that we sometimes do ad-hoc backups to tape of some of these individual jobs.  However, my coworker had a great idea - run a single-file backup job as overwrite only as a "delete" job since you can't schedule erase tape jobs.

So instead of using our first job in the series as an overwrite, backup a single text file as the first job as overwrite to start the series at the beginning of the tape.  Since we'll never need to run that backup of a single file on an ad-hoc basis, we can keep the actual backup jobs set to append then terminate...

Thanks for the response!  Anyone else have different suggestions?