Raghu S wrote:
Hi,
There was a lot of discussion on this topic before.But i am requesting TSM
gurus give their comments again.
The set up is like this.
TSM Server : Windows NT 4.0 SP6, TSM 5.1.0.0
392 MB memory, P III
Adaptech Ultra SCSI
Hard Disk : Internal Hardware RAID 5:
array A : 8.678GB * 3 : 17.356GB data and 8.678 GB
parity
array B : 35.003 GB * 3 : 70.006GB data and 35.003
GB parity.
Both array A and array B are connected to the same channel.
OS and TSM 5.1 are installed on array A
TSM data base, recovery log and Disk storage pool are installed in array B.
Database : 2GB+2GB = 4 GB and mirrored at TSM level on the same array
Recovery Log : 500MB + 500 MB = 1 GB and mirrored at TSM level on the same
array
Disk Storage pool : 10GB+10GB+10GB+10GB+5GB=45GB on array B
TSM client: 4.1.2.12 ( Tivoli says 4.1.2.12 is not supported with 5.1
Server. But i could take the backup,archive and restore with this
combination )
Number of Clients : 55, all are windows
Incremental backup : 1GB/ client/day.
backup window : 9AM to 6PM with 50% randamization ( all are in polling mode
)
LAN : 100Mbps
End of the day only 10 clients could finish the backup.Remaining all are
missing or "?" ( in progress ) or failed.
Through the entire backup window the CPU load is 100% with dsmsvc.exe
holding 98%
I tested with various options. I stopped the schedular and fired 3 clients
backup manually at the same time.Each client has 1 GB of incremental data.
It took three hours to finish the backup. While backing up i observed there
was lot of idletime outs of sessions.
Network choke is not there. I checked this with FTP.
Whats the bottleneck here? Is RAID 5 is creating problems ( DB,log and
storage pool all are on the RAID 5 )? I asked the customer to arrange a
testing machine without any RAID. I will be getting that in two days.Before
going on to the testing i like to know your comments on this.
Regards
Raghu S Nivas
Consultant - TSM
DCM Data Systems Ltd
New Delhi
India.
e-mail: [EMAIL PROTECTED],[EMAIL PROTECTED]
Hi,
Well you have heard several answers so far so I won't repeat what they
have said, but I would like to add a couple of new things that can
improve you performance.
* First of all 392MB of memory isn't enough for a desktop machine
today let alone a server. Windows performance is very much
dictated by the amount of memory it has. I would upgrade to at
least 2GB, you might get by or at least see improvements with 1GB,
but 2GB will be much better.
* You don't mention your network config, but having multiple NICs
will help. Also, make sure your are using "full duplex"mode if at
all possible.
* You are using polling, I prefer server prompted because I can
better control the load on my system by tuning it with
"maxsessions" and "maxschedsessions". With server prompted I can
bring the server upto peak operating load rapidly and keep at its
peak until the client load starts to reduce due to client backups
completing. Backup windows are always considerably smaller using
this methodology.
* If you must stick with polling then reduce your randomization to
about 25%. Also, make sure that your "maxsessions" and
"maxschedsessions" are set to accomadate the load.
* All your drives are on one SCSI bus, this is bad! Add more SCSI
controllers or at least take advantage of multiple channels on the
same card.
* Take ITSM DB and LOG off of RAID 5 and just use ITSM mirroring.
* Make sure LOG and DB are not on same drive(s)
* But LOG and DB mirrors on different SCSI bus from primary
* You must decide if you need to protect your storage pool with RAID
or not. This can be one of those philosophical debates, but you
must decide that in the event of a disk crash can you afford to
loose a nights worth of backups, i.e. can it easily be retrieved
from the client or has the data already been changed.
* If you don't need the protection of RAID 5 for your storage pools,
then make one volume per drive. Again spread these across SCSI
channels and controllers if possible.
There have been many posts on this list about performance tuning so you
can refer to them if you need to. However I am willing to bet the
biggest problem here is the limited memory. The next biggest problem is
the disk configuration.
Regards,
Mark D. Rodriguez
President MDR Consulting, Inc.
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