Ultrium Poor Performance (Win2K)

[David Rawling]

I have a server with what appears to be an HP half-height Ultrium tape drive. It's been rebadged as an IBM but the firmware shows up as HP Ultrium 1-SCSI v N15G [information from Backup Exec Device Configuration screen].

The device is connected as SCSI ID 5 on it's own channel of an Adaptec AIC-7899 SCSI controller.

The hard disks in the server consist of a RAID-1 set for OS and RAID-5 for data. All hardware RAID of course.

The problem is that no matter what device driver I use for the tape drive, the maximum tape throughput I can achieve is 2MB/sec.

I have tried both the HP v3.0 driver and the Veritas driver; both achieve near identical throughput.

Other relevant information:
* Backup Exec 8.6 device configuration is 64K block size, 1024K buffer size, 10 buffers, 7 high-water.
* SCSI controller driver is branded Adaptec with no version number (included with Win2K).
* Server is 1.266 GHz PIII (single) with 768M RAM and 280M working set. Tuned for file services and background services.
* PAT tool estimates disk throughput at 14MB/sec on the RAID-1 set .. but fails on the RAID-5 set with an error.
* For Backup Exec, the device has been configured to be exclusively available to BE.

Any further details that people want ... please post as I am monitoring this question.

Thanks in advance,

Dave.

[Alexander M. Ermes]

Hi there.
Is your Ultriium drive daisychained to something else ?
If yes, that might be the problem. The drive needs one interface on its own.
Rgds
Alexander M. Ermes

[David Rawling]

The Ultrium is indeed on it's own dedicated channel.

There is an article on the IBM website regarding such performance problems. The URL is:

http://ssddom02.storage.ibm.com/tape/lto/devdriver.html

The note is right at the bottom of the page, under the heading Windows 2000.

I have therefore replaced the Adaptec drivers that were installed with the server setup CD, with the normal Microsoft drivers. The problem persists.

[Jan Klier]

One other thing to consider is cooling. This particular drive is a half-height drive and does require proper cooling. It actually monitors its operating temperature and if it overheats it will limit its performance to avoid damage.

[Graham Rawolle]

What version of firmware does your 215 have? I upgraded ours from N16D to N20D two days ago and have noticed a huge performance increase. Previously we were only getting a disappointing 2MB/s. Since the upgrade we are getting between 4.4MB/s (for a disk with huge numbers of small files) and 13MB/s (for a disk with large contiguous log files). We are using BackupExec 8.6 and Windows 2000 and similar hardware to you (dedicated onboard Adaptec AIC-7899 SCSI and separate RAID controller etc)

[Dan Moesch]

Aside from the looking at the Tape Drive and Backup Exec settings, have you looked at the disk system of this server?

Sounds like something might be going on with the RAID controller on that server.

Try attaching another backup device to the server and see how the performance is.

[David Rawling]

The disk susbsystem, at least for the operating system, should not be a bottleneck. I can move 14-20 MB/sec on that subsystem; and on the RAID-5 subsystem can read at > 20MB/sec; so I don't really believe it is the disks.

An IBM engineer is supposed to be attending to site to update the tape firmware - I'm hopeful that this resolves the problems.

[Kevin Longley]

I have a simialr problem. Were you able to correct it?