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Ultrium 960 slow! Please help a noob

Frequent Advisor

Ultrium 960 slow! Please help a noob

Hi all,

I have just posted a related post in the SAN forum, but thought a more specific request was necessary for this..

Jist is, just changed jobs and the existing team have been putting up with incredibly slow backups. Which I thought I should try to fix!

Equipment is a HP Server ML530G2 with a LSI Logic Ultra 320 Dual Channel SCSI card. No internal connections. On channel A an external Ultrium 960 sits, on channel B an external SDLT 320 sits.

First question, does a SCSI bus include both channels (Or is a bus another term for a channel). I ask this because I have heard SCSI buses will drop all device speeds down to the lowest speed, and if anything plugged in to the card is part of the bus, then the SDLT is probably slowing it down!..

I hav run HP L&TT on the Ultrium 960 and it states that the following:

Current SCSI configuration: narrow Recommended: wide
Current SCSI transfer rate limited to: 40 MB/sec. Recommended: 320 MB/sec. or better

I am hoping someone is going to reply and state that getting the SDLT off the LSI card is going to fix this?

Regarding the SDLT, I was looking up its specs to see what it can do, and HP's site stats it is ultra 2 scsi with a sustained transfer rate of 16MB's with a burst of 80MB's..

Is that ultra 2 narrow or wide? or both (The reason I ask this is because narrow can do 40MB whilst wide can do 80MB?... and also if it can only do 40MB how does it obtain 80 in a burst mode??!!

Sorry that is a lot of questions.. I am desperately looking to learn!
Honored Contributor

Re: Ultrium 960 slow! Please help a noob

according to what ltt says, you may have a se terminator instead of a LVD, or you may have a bent/broken pin on one of the connectors of the cable or terminator, also you may have a bad cable

the fact that the negotiation is narow mean that the bus is using only 8 bits out of 16, and during the domain validation process, the communication has been negotiated to 40 MB/s

fix this first and then the backup shoudl run as expected

Honored Contributor

Re: Ultrium 960 slow! Please help a noob

If it's not a fault as Marino described, it could also be a BIOS setting on the LSI card. Is there an option to change settings on the card as the system boots up?