Karel Bos & Paul Banes,
Thanks for the response!
I will look into the 'correct' drivers and level of drivers as an issue.
We did have to 'de-rate' the 160MB/sec controller to a 80MB/sec to get
it to work (evidently a LTO problem working with SCSI communications at
a higher rate). This was done with help from IBM support. (This is done
in the controllers 'BIOS'.) Even at the 80MB/sec rate it should be more
than enough to support two LTO drives. I even varied one of the drives
offline on each controller, and got the same throughput rates.
How do I know the speed? Just from observation. The amount of data in
MB in a storage pool times its percent full, get a single tape backup
started from that disk pool to tape. Wait till a decimal portion of the
percentage full changes, log that time. Wait for an hour or so, then
again check for the decimal portion of the percentage change. Calculate
the number of MB that it represents, and divide by the time to get the
rate. And I have done the similar thing for a database backup from
start to end. It is a time consuming and manual process.
I have also tried the storage pool comparison with multiple tape
streams, and the rate per drive per unit of time is still consistent.
In the past, I have checked the CPU and memory loads. The CPU is
loafing, and memory does not seem to be taxed. The only disk issue I
have seen is when doing some disk intensive work the i/o queueing to
disk goes through the roof. (I am trying to get more spindles to help
with this.)
I only have TSM drivers installed on this box for the LTO drives. But I
may have to do that.
... Jack
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Bos, Karel
Sent: Wednesday, January 26, 2005 10:30 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: How to get a tape drive to stream?
Hi,
First of all, I remember some issues with Adaptec cards, LTO drives and
performance problems. If I recall correctly you have the install the
correct driver version of some Adaptec cards from a fresh installation
of Win2K to not get hit by that problem.
Then, "I can't get", what process are you running to check the
performance of the drives. You have your DB, logs and diskpool volumes
all on RAID5 sets. If you are running test, do you have some performance
counters running on this like memory / cpu / disk IO?
Some test to see if the TSM server is the bottle neck could be things
like directly writing a large file to tape (from outside TSM).
Last, but not least. Why version 4.3?
Regards,
Karel
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Coats, Jack
Sent: woensdag 26 januari 2005 17:16
To: ADSM-L AT VM.MARIST DOT EDU
Subject: How to get a tape drive to stream?
But does someone have a pointer to some 'tips & tricks' or FAQ to help
me get these LTO tape drives streaming with TSM on Windows 2000?
The drives seem to be doing about 3MB/sec per drive, no matter what is
going on in the server. This is about the right speed for stop/start
programmed I/O processing.
My config is TSM 4.3 on Windows 2K server (2 1.2G Xenon, 1G RAM)
My SCSI attached LTO-1 drives are on Adaptec controllers (IBM branded),
with two tape drives per controller. I have 3 identical SCSI
controllers with two drives each (one also has my 3583 library on it).
Disks (6 72G 10K drives, in two partitions) are attached to one RAID
card, and are RAID 5.
I can't get just running a single tape drive streaming, with nothing
going on in my system (db backup only, no backups, no reclamation, no
expiration, etc)
Any advice/suggestions are appreciated. ...
... Desperate in Houston ... JC
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