My customer is asking me some interesting questions I can't say I know how to answer - regarding moving volumes and allocation of scratch volumes across multiple libraries.
The system uses IBM's Content Manager OnDemand product to archive documents -- which relies on TSM for long-term storage and storage management. The questions are fairly straightforward, and any information the group could bestow would be greatly appreciated.
The questions are quite general, but just to be clear... I'm running AIX 4.3.3 on p/Series (6H1) with TSM 4.2.3.0. Connected to the server is one LTO library, and currently one 3995 Optical Jukebox with about 100 optical platters in it. In the very near future, a second and third optical jukebox will be added. Due to the legal requirements, all data stored on Write-Once (WORM) media.
When the second library is added, the question quickly becomes:
Can we move optical platters out of one library into another, to spread out the distribution of data, and 'load balance' retrievals across the additional 6 drives?
My first inclination is to say 'No' because a device class includes the library as part of it's definition. Would checking out a volume from one jukebox and checking it into another jukebox change it's device class, or merely update the 'library' field in the volume's record? I'd try this out now, but I don't have that second jukebox yet.
I know that the obvious solution is to 'move data' from a number of volumes to the newly installed jukebox -- and this would be my recommended solution, if the data weren't stored on expensive WORM media which apparently cost 80GBP each.
The follow up to that question is this:
If each library has a number of scratch volumes, and a new volume is required, how are the scratch volumes allocated to storagepools? Will a storagepool only claim a scratch volume from it's own library? If there are no scratch volumes in the current library, will it use one from another library? What is the best way to manage this without having to micromanage each jukebox? We're also trying to ensure that a copy storagepool for data stored on opticals does *not* reside in the same jukebox, for redundancy and availability reasons.
There is potential for this system to include up to 9 optical jukeboxes in the near future. What questions need to be asked and decisions need to be made to ensure that the future is maintainable by mere humans?
As always, thanks in advance for all your assistance and insight. I've been a subscriber to ADSM-L for over two years now, and find the collective skills of the list an exceptionally friendly resource for my toughest questions. In short... Thank You. =)
-JD.
