Media Sets vs. Partitions

[Nicolas_Fahr]

Hi,

from what I understood
- Media Sets should be used to define append periods and overwrite periods
- Partitions should be used to define which slots should be taken for backup jobs

Ok, let's say I have a backup rotation plan where I need to store some tapes offside. Then I would have to options.
The first option would be to use a Media Set for - let's say monthly - backups. Then I could use a rule for offsite storage in conjunction with Backup Exec's reporting mechanism to send me an notification which tapes needs to be pulled out of the library and which barcode labeled tapes should be taken back into the autoloader.
The second option would be a separate partition for those monthly backups so that the backup operator would take the tapes once a month out off the autoloader and puts others in as desired.

From my understanding, both solutions fit the same backup strategy. So I am asking what's the better way, option 1 or 2?

I guess it's harder to configure option 1 with all these fine tuned media set properties, but then the operator just need to work down the autogenerated list once a month. Then he knows exactly which tapes to take out and which be must bring in.
For the second option, I think it much easier to configure in Backup Exec, but for the operator it's much more work (and a probably human point of failure) to determine which tapes from which month he needs to bring back to the robot. Let's say, now it month #11, and he brings back the tapes from month #10 instead of those from month #8. Then the #10 backups would be overwritten by mistake.

I see that it's hard to compare Media Sets and Partitions, but I am asking myself which way I should go. How can both strategies work together? What do you think?

[Keith_Langmead]

You shouldn't really think of the two of them as different options, rather they're two things which work together.

Of your two options I'd personally go with the second one but with a twist. Create a partition for the monthly backups, but also create a Media Set specifically for your monthly backups, something like 11 months overwrite protection (assuming you had a 12 month rotation). Then set your monthly backup job to point to this partition and use this media set, so your operator can easily see which tapes need to be removed, and in the event the wrong tapes are inserted the old data won't be overwritten ahead of time.

Once you have that working you could also get the reporting setup to give the notifications to your operator about which tapes to insert each month, but having never set that up myself I can't judge how hard that is.

[Nicolas_Fahr]

OK, so this means that there is a direct relationship between the media set and the partition (at least in this case): in one partition there is one media set beeing used. Is this a common strategy or am I going the wrong way?
And when backups get more complex, it probably makes sense to create different media sets within this partition, maybe one media set for storage data and another one for databases or exchange data, system states.... Does this make sense?

[Keith_Langmead]

Kind of yes, though I wouldn't refer to it as being a relationship between the media set and the partition, since that's misleading.

The two things are very much mix and match, but I think in most cases a lot of people will keep it fairly simple.

Just think of it as you use the media set to control how long the media is protected from being overwritten, and how long it can be appended to following the first backup, and the partition controls which tapes are used for the backup, either individually, or to within a subset of the tapes in the entire library.

Where I think you need to be careful is if you use multiple media sets on jobs which all use the one partition. If each job is just supposed to use its own tape then you're fine, but I think once a tape has been allocated to a media set it can't then be used by another job using a different media set.

Hope that makes sense.

[Nicolas_Fahr]

Keith, thanks for your explanation.

Now I will give it a try with one partition and one media set. I will create some Jobs, one for our NAS, one for Exchange, another one for SQL and one for System States, AD... All these jobs then go to the same Media Set. I think from time to time, I then need to review my strategy and reconfigure BE as desired.