Roger,
You certainly want to get a "best guess" list of likely priority#1 restores.
If your tapes really are mostly uncollocated, you will probably experience lots
of
tape volume contention when you attempt to use MAXPRocess > 1 or to run multiple
simultaneous restore, move nodedata, or export node operations.
Use Query NODEData to see how many tapes might have to be read for each node to
be
restored.
To minimize tape mounts, if you can wait for this operation to complete, I
believe
you should try to move or export all of the nodes' data in a single operation.
Here are possible disadvantages with using MOVe NODEData:
- does not enable you to select to move only the Active backups for these nodes
[so you might have to move lots of extra inactive backups]
- you probably can not effectively use MAXPROC=N (>1 nor run multiple
simultaneous
MOVe NODEData commands because of contention for your uncollocated
volumes.
If you have or can set up another TSM server, you could do a Server-Server
EXPort:
EXPort Node node1,node2,... FILEData=BACKUPActive TOServer=...
[Preview=Yes]
moving only the nodes' active backups to a diskpool on the other TSM server.
Using
this technique, you can move only the minimal necessary data. I don't see any
way
to multithread or run multiple simultaneous commands to read more than one tape
at
a time, but given your drive constraints and uncollocated volumes, you will
probably
discover that you can not effectively restore, move, or export from more than
one tape
at a time, no matter which technique you try. Your Query NODEData output
should show
you which nodes, if any, do *not* have backups on the same tapes.
Try running a preview EXPort Node command for single or multiple nodes to get
some
idea of what tapes will be mounted and how much data you will need to export.
Call me if you want to talk about any of this.
--
Jim.Owen AT Yale DOT Edu (w#203.432.6693, Verizon c#203.494.9201)
Roger Deschner wrote:
MOVE NODEDATA looks like it is going to be the key. I will simply move
the affected nodes into a disk storage pool, or into our existing
collocated tape storage pool. I presume it should be possible to restart
MOVE NODEDATA, in case it has to be interrupted or if the server
crashes, because what it does is not very different from migration or
relcamation. This should be a big advantage over GENERATE BACKUPSET,
which is not even as restartable as a common client restore. A possible
strategy is to do the long, laborious, but restartable, MOVE NODEDATA
first, and then do a very quick, painless, regular client restore or
GENERATE BACKUPSET.
Thanks to all! Until now, I was not fully aware of MOVE NODEDATA.
B.T.W. It is an automatic tape library, Quantum P7000. We graduated from
manual tape mounting back in 1999.
Roger Deschner University of Illinois at Chicago rogerd AT uic DOT edu
On Tue, 22 Jan 2008, Nicholas Cassimatis wrote:
Roger,
If you know which nodes are to be restored, or at least have some that are
good suspects, you might want to run some "move nodedata" commands to try
to get their data more contiguous. If you can get some of that DASD that's
coming "real soon," even just to borrow it, that would help out
tremendously.
You say "tape" but never "library" - are you on manual drives? (Please say
No, please say No...) Try setting the mount retention high on them, and
kick off a few restores at once. You may get lucky and already have the
needed tape mounted, saving you a few mounts. If that's not working (it's
impossible to predict which way it will go), drop the mount retention to 0
so the tape ejects immediately, so the drive is ready for a new tape
sooner. And if you are, try to recruit the people who haven't approved
spending for the upgrades to be the "picker arm" for you - I did that to an
account manager on a DR Test once, and we got the library approved the next
day.
The thoughts of your fellow TSMers are with you.
Nick Cassimatis
----- Forwarded by Nicholas Cassimatis/Raleigh/IBM on 01/22/2008 08:08 AM
-----
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU> wrote on 01/22/2008
03:40:07 AM:
We like to talk about disaster preparedness, and one just happened here
at UIC.
On Saturday morning, a fire damaged portions of the UIC College of
Pharmacy Building. It affected several laboratories and offices. The
Chicago Fire Department, wearing hazmat moon suits due to the highly
dangerous contents of the laboratories, put it out efficiently in about
15 minutes. The temperature was around 0F (-18C), which compounded the
problems - anything that took on water became a block of ice.
Fortunately nobody was hurt; only a few people were in the building on a
Saturday morning, and they all got out safely.
Now, both the good news and the bad news is that many of the damaged
computers were backed up to our large TSM system. The good news is that
their data can be restored.
The bad news is that their data can be restored. And so now it must be.
Our TSM system is currently an old-school tape-based setup from the ADSM
days. (Upgrades involving a lot more disk coming real soon!) Most of the
nodes affected are not collocated, so I have to plan to do a number of
full restores of nodes whose data is scattered across numerous tape
volumes each. There are only 8 tape drives, and they are kept busy since
this system is in a heavily-loaded, about-to-be-upgraded state. (Timing
couldn't be worse; Murphy's Law.)
TSM was recently upgraded to version 5.5.0.0. It runs on AIX 5.3 with a
SCSI library. Since it is a v5.5 server, there may be new facilities
available that I'm not aware of yet.
I have the luxury of a little bit of time in advance. The hazmat guys
aren't letting anyone in to asess damage yet, so we don't know which
client node computers are damaged or not. We should know in a day or
two, so in the meantime I'm running as much reclamation as possible.
Given that this is our situation, how can I best optimize these
restores? I'm looking for ideas to get the most restoration done for
this disaster, while still continuing normal client-backup, migration,
expiration, reclamation cycles, because somebody else unrelated to this
situation could also need to restore...
Roger Deschner University of Illinois at Chicago rogerd AT uic DOT edu
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