Greetings,
This is an TSM 5.4.3.0 server, TSM 5.4.2 client environment. AIX
5.3ML5 servers, AIX 5.3 and Win2003 clients. Multiple TSM servers share
a virtual tape library and a physical tape library via TSM library
sharing.
We have been gradually migrating from traditional disk pool to a
virtual tape environment, and have begun getting a lot of messages like:
ANR0539W Transaction failed for session 163135 for node APLORA01. This
node has exceeded its maximum number of mount points.
It looks to me like our set up is right, and "resourceutilization" is
not working as documented. I know, you've heard that before! But hear
me out. Here is the table from the Performance Guide:
RESOURCEUTILIZATION value Maximum number Unique number of
Threshold
of sessions producer sessions
(seconds)
1 1 0 45
2 2 1 45
3 3 1 45
4 3 1 30
5 4 2 30
6 4 2 20
7 5 2 20
8 6 2 20
9 7 3 20
10 8 4 10
0 (default) 2 1 30
I misunderstood this before, but a "producer" session is one that scans
a file system looking for files to backup. The rest of the sessions are
"consumer" sessions that send data to the TSM server. Right?
If so, according to this, a "resourceutil 10" should not be asking for
more than 4 tape drives. If the max is 8, and there are 4 producer
sessions, then there should only be 4 consumer sessions, righrt? And
here is a recent list of some of the servers getting the errors:
NODE_NAME PLATFORM_NAME KEEP_MP
MAX_MP_ALLOWED
------------------ ---------------- ------------------
--------------
MAXORA01UT AIX YES
4
RMNORA02 AIX YES
4
MHPORA01D AIX YES
4
APLORA01 AIX YES
6
TECDB02 AIX YES
4
TIBORA20 AIX YES
6
MAXORA10T AIX YES
4
GRDORA01 AIX YES
4
CREDORA01 AIX YES
4
So why are they getting the error? Why should any of them mount more
than 4 mounts? The only thing I can think is that it does not work the
way it is documented. We are not running multiple TSM schedulers on the
same server, or anything like that. (These machines also run Oracle
RMAN backups, but through a separate TSM client definition, i.e.
APLORA01_ORACLE, so it will not interfer with the number of tape mounts
allowed for this client.)
One thing we thought is the keep_mp being yes might create a situation
where a tape was filled, and while it is dismounting, TSM tries to mount
another tape, but that pushes it up over the threshold. But I don't
think that can be it; we increased a couple of the clients to maxnummp=6
as you can see, and it still happens.
I know some of you will just say to increase maxnummp to a large number
and forget it; but we have a finite number of virtual tape drives, so we
can't go that way. We are thinking we may just drop "resourceutil" to 4
to see how many tapes it mounts then.
Best Regards,
John D. Schneider
Lead Systems Administrator - Storage
Email: John.Schneider AT Mercy DOT net
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