HP Ultrium 215 is SLOW :-(

[Marino Meloni_1]

hi Tim
Temperature could be effectively the cause, if overtemp is reached, the speed is decreased.
If the unit is an internal one, check inside the server in order to be sure that the scsi cable are not passing in front of the air flow, this is the higher cause of over heating for Ultrium inside of servers.
The temp is mesured in differents parts inside the unit, that is why these data are not the same as the temp inside the server.
check here for tuning performances on LTO
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=lpg50460#P180_15521
marino

[Dave Dewar]

Hi Tim,

The Ultrium 215 will only slow down to 6MB/s if it detects it is running over temperature, no lower.

However, a secondary effect might be that under excessive over temperature the write/read performance of the unit could be impaired and consequently the unit might have to do more rewrites to ensure the user data on the tape is recoverable. This would require the unit to reposition more and so the effective transfer rate as seen by the host would be less than 6MB/s, maybe even as low as the the 1.85MB/s you are seeing.

There are two temperature sensors inside the Ultrium 215. One is positioned in the tape path to measure media temperature, this is refered to as tape path temp in LTT I believe and typically measures between 5 and 20degC higher than the ambient temperature external to the unit depending on airflow though the unit. Under conditions of very low airflow this delta can rise to close to 20degC. The second sensor is mounted within the backplane electronics at the rear of the unit and measures electronics temperatures, this can be anywhere between 15 and 40degC above ambient depending on airflow. Low airflow will yield a 40degC delta.

The tape path sensor is the one that is used to be the drive to determine over temperature conditions, speed limiting and tape alert flag reporting and LTT cooling check tests. Sensor 2 is not used at all except for logging purposes.

The ambient spec of Ultrium 215 is 35degC and the airflow requirement is 5CFM through the front panel. From your result of 50degC for tape path it does sound like you are running outside specifications although I would have to see a support ticket to be sure.

If you want, you could post a LTT support ticket here and I'll take a look at the temperatures reported and the write/read performance as well. Generate a support ticket after running either the LTT cooling check or a backup and leave the tape in the drive when you create the ticket so that I can see the tape logs as well.

The other option you could try is to remove one of the units and try running it externally if possible to see if you get better performance. This would require you to have a suitable enclosure and cabling etc and so might not be practical long term, but would be useful from an experimental "proving the thermal theory" viewpoint.

Cheers,

Dave Dewar

[Tim Patton]

Everyone,

I finally have good news. This took a lot of effort to get it working properly. The short answer is that after a lot of searching, I came across the following HP website

http://h20004.www2.hp.com/soar_rnotes/bsdmatrix/matrix62462de_DE.html

If you click on the "info" button beside the win2k driver, you'll see the following

"The revision of the driver negotiates synchronous transfer rates with non-disk devices such as HP Ultrium Tape drive, and all subsequent I/O transfers now occur asynchronously.Tape I/O Test certification failure fix"

Now, as I mentioned above, I had tried drivers before, direct from Adaptec's website for the C7474A. However, they kept saying I already had the latest drivers. But, after reading what this driver did, I thought I would try it anyways. To my surprise it allowed me to install this driver for the controller.

According to device manager, the driver went from:

Adaptec SCSI Card 29160LP Low Profile Ultra160 SCSI
Driver Provider: Adaptec
Driver Date: 3/15/2000
Driver Version: Unknown Version

After the driver upgrade, the driver went to:

Adaptec SCSI Card 29160LP Low Profile Ultra160 SCSI
Driver Provider: Adaptec
Driver Date: 2/21/2001
Driver Version: 4.2.0.0

I rebooted the server, and started a backup. I'm currently getting over 800MB/MIN!!! My 120GB data store should be backed up after about 2h20min!!!

Thanks to all who replied, and tried to help. Obviously you can't trust comparing .sys driver versions. I am now a huge fan of the Ultrium 215 tape drives :-)

I hope this is of some info to anyone else who has speed problems with their HP Ultrium tape drives.

Tim

[Rob_251]

The subject of Tim's email seems to echo a problem that I have been having. I tried to go to the link that was given in his final post, but it doesn't work for me. Does any body have any information on how I could get to that site. Any help would be greatly appreciated.

[Tim Patton]

You are correct, it appears the HP link is down...you can go direct to adaptec's website, and download the new drivers from there

http://www.adaptec.com/worldwide/support/drivers_by_product.jsp?sess=no&language=English+US&prodkey=ASC-29160LP&cat=%2fProduct%2fASC-29160LP

(There are NO SPACES in the above link)

I also highly recommend updating the card to the 3.10 bios revision.

Good Luck!
Tim

[Rob_251]

Tim, thank you very much.
Rob

[Tim Patton]

Since the problem is solved (as listed above), there doesn't seem to be any reason to keep this thread open. Closing thread