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" <ADSM-L AT VM.MARIST DOT EDU> 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.
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