You may also want to look at your VMM options. Can you cut and paste the
output from a vmtune -a command to this post? (Or ioo and voo, whichever
you want).


At 04:54 PM 4/12/2005 +1000, you wrote:

Dear All,

TSM Server 5.2.4 on AIX 5.2 with 6 GB memory. (p690 lpar)
3592 tape drives fibre attached.
TSM Backup/Archive client 5.2

I have a large number of 2 GB files to archive directly to tape - the files
are within filesystems on a SAN storage device. If I mount the filesystems
locally on my TSM Server and archive them, I get a rather disappointing 22
MB/s when archiving to a single tape drive.

If I archive the same data in the same filesystems but by mounting them
onto a remote AIX server and running the 'dsmc archive' command and send
them over the Gb lan, then I get a far more satisfactory 37 MB/s (again,
archiving to a single tape drive).

Why should performance archiving over the network be better than archiving
locally? My remote server is similarly configured to my TSM Server - same
version of AIX, backup/archive client, similar memory etc.

I have tried using SHAREDMEM but it made no difference. Also tried raising
the TCPW from 64 to 128, no difference. Tried a TCPBuffsize of 512 instead
of 32, no difference.

Indeed my client options are the same on both the TSM Server and the remote
server.

Any suggestions gratefully received.

Server Options
=============
BufPoolSize             512288
TCPW                        64
TCPNODELAY       YES
TXNGROUPMAX   256

Client Options
============
COMMmethod        TCPip
Compression          No
TXNBYTELIMIT     2097152
TCPBUFFSIZE        32
tcpwindowsize        64
TCPNODELAY      Yes


Regards,

Eric Winters
Australia

Dave Canan
TSM Performance
IBM Advanced Technical Support
ddcanan AT us.ibm DOT com