Hello, I have a follow up question.
I see that you have 3 storage pools. Can you tell me what "COPY" storage is used for? is this one used like similar to Primary or are you making copy of Primary? Primary ---> Copy----> Offsite (goes to offsite) or Primary ------> copy (goes offsite) ------->Offsite (goes offsite) Sung Y. Lee Sung Y. Lee "ADSM: Dist Stor Manager" <[email protected]> wrote on 02/11/2005 11:34:46 AM: > Hi, all: I've got a question I've been wondering about, relating to how > foresightful TSM is in its' offsite reclamation. I'll spin an example: > > > TSM server 'SRV1' has three nodes > > NODE1 > NODE2 > NODE3 > > It's got stgpools > > PRIMARY : collocated . Volumes named Pxxx > COPY : non-collocated . Volumes named Cxxx > OFFSITE : non-collocated . Volumes named Oxxx > > Daily incrementals happen on all nodes. > Tapes go offsite every day. > > > OK, given that scenario, we know that the vast majority of offsite tapes have > a thin slice of data from all of NODE1, NODE2, and NODE3. > > > --- Known scenario --- > > So when an offsite volume O213 passes the reclamation threshold, the server > begins building a new offsite volume O501. > > It mounts PRIMAY volume P001 (with node1's data on it) and makes an additional > copy of those files from NODE1 that appear on O213, and are still interesting > to the server. > > Then it mounts PRIMARY volume P002, does the same for NODE2, > > Then it mounts PRIMARY volume P003, does the same for NODE3. > > > Now, new offsite volume O501 is ready to leave on the next truck. > > > --- Unknown scenario --- > > Now, what if O214, O215, and O216 all pass the reclamation threshold? We know > the server's going to start building O502. Say it picks O214 to begin with. > > When P001 is mounted, will the reclamation copy files from -all- the > reclaimable offsite volumes, only from O214, or what? > > > > > I can see pseudocode something like: > > - Pick an offsite volume to work on > - From that offsite volume, pick a first onsite volume to mount > - From that onsite volume, determine all files wanted for offsite > reclamation. Copy them. > > This would be expensive in query time, but the alternative is a big-O N * M of > tape mounts, which makes me shudder. But it would certainly be simpler to > code.
