SCSI Question

[CA1168770]

Hi,

I am running a HP Proliant G3 380, Windows 2003. Attached is a HP StorageWorks LTO Ultrium2 tape drive to the scsi port on the back. Recently we have been having slow verify times with our backups (backup exec 9.1), it has been running fine for 9 months. Called veritas and they recommend that I add another scsi card to the box and plug the tape drive into that and not into the scsi port that has the raid on it. The funny thing is only half of the backups have slow verify and the rest are fine. I think veritas is trying to pull the wool over my eyes here. Can anyone see the reason for adding a second scsi card?

[CA984331]

Hi,

if it is only the half of the tapes and you backup the same amount it may be tapes getting old and developing writing problems. Are you using cleaning tapes regularely? Are you sure, the raid and tape are on the same scsi bus? Is that a software or a hardware raid?

greetings,

Michael

[CA1168770]

Hi Michael,

I have been cleaning the tape unit on a regular basis. It has now been confirmed that the tape and raid are on the same bus and it is a hardware raid. Recently I have used brand new tapes and I still have the problem. Thanks for your inquiry.

[CA984331]

Hi,

there is merit to what veritas says.
Other peripherals on the bus - high-speed tape drives must have exclusive access to the HBA/bus to achieve their potential bandwidth. Also, SCSI devices negotiate to match the lowest speed device on the bus - a legacy device can bring everything else on the bus to its knees

This is a recommandation from HP which I have also heard. Try the LTT tool for a performance test.

greetings,

Michael