On 17 jun 2009, at 06:43, Steven Harris wrote:
Hi All
A bit of explanation first... bear with it there is a point.
One of my customers is implementing a big SAP landscape on AIX. The
design
has multiple P595s with many lpars. Backup was to be via hardware
snapshot of volumes to San Volume Controller in front of DS8000
disk, which
then get re-mounted and backed up using TDP for SAP. One lpar in
each P595
is a TSM server and so data flows from client to server along a
virtual
backup network inside the P595, however this network is externalized
and
may be used to back up windows, MSSQL, exchange and other sundry
bits and
pieces that don't run on AIX.
There is a new-ish facility of the Power boxes called Live Partition
Mobility. If an lpar is properly set up so that all its resources are
virtualized and external, it can be suspended, moved to a different
physical machine and revived in a very short time - this facility
is much
like the thing VMWare can do for those of you not familiar with Power
hardware. The next part of the implementation is set to use this
facility.
The issue is that should an lpar move to another physical machine,
then the
backup path will not flow internally along a very fast pipe but
externally
across the LAN. This will be unacceptably slow, as it must be
possible to
make a whole backup in 6 hours before the space is needed for the
following
snapshot.
One possibility would be to install TSM for SAN on the partitions
that need
it, but there is some administrative overhead with doing this, and
we are
finding that drive sharing is not as error free as we would like
with only
a 5 way split. We are seeing drives getting hung up with reserves,
and are
afraid that this will get much worse if more AIX lpars share them.
This is not my experience, so things are not as they should be. I
believe that the LAN-free agent is quite ok at this time, and the
administrative overhead is quite limited.
Once upon a time, it was mooted that disk controllers would be smart
enough
that Server free backups could be done, that is the disk controller
talks
direct to the tape drive across the SAN and the data does not need
to pass
through the client that originally requested the backup, I believe
this
was the original intent of the DATAMOVER options in the define path
commands. I also dimly remember seeing a white paper about an array
backing up direct to a SAN data gateway on an old 3583 library,
I have been noodling about the IBM site and google and have not found
anything. Can the SVC/DS8000 combination be used to backup my SAP
volumes
server free to a TS3500 library ? If so can anyone point me to
appropriate
documentation?
server-free is a dead concept, it will never happen.
Thanks for persisting this far , and thanks in advance for your
assistance
could you, on the lpar in charge of backing up you sap data, run a TSM
server? Maybe make it a bit bigger and combine the two tasks? I run
(as a test) a TSM server on an OCFS2 (clustered filesystem) node
without any problems. You can then use sharedmem client/server
communications, I'm sure things will fly ;-)
Steve
Steven Harris
TSM Admin
Sydney Australia
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