Slow backup rate

[NotApplicable]

Hi, I am using BEW10d with a Compaq SDLT 320 external tape drive. I have been getting some errors which are: An invalid command was sent to the storage device.

One of the things I did to resolve was to update the symantec tape driver and ever since the throughput is 33Mb/s whereas before it was over 300. I can not find later drivers, if any one could assist with some advice or links that wouldbe great because so far I have come up with nothing. Currently I back up over 200Gb so 33Mb/s is not good enough.

[Ken_Putnam]

Was updating the drivers the only thing yo did?

Also, from the Devices Tab, right click the Drive\Properties

What are the settings for Block Size, Buffer Size and Number of buffers?

Also the settings for both Single Block settings, and both PassThru settings?

[NotApplicable]

Hi, Thanks for coming back to me on this Ken. As you know there are some support articles on the initial error message with some causes. Everything else was alreday covered such as Device Firmware and ensuring that the device is on its own SCSI controller instead of using a RAID controller etc. The only outstanding thing was to update the drivers, which bought me to the slowness. I also ran a device test with HP Tape Tools which did in fact pass.

Ideally what should the block buffer and number be set at?

[NotApplicable]

HI,

Block Size 64K

Buffer Size 64K

Buffer count 10

High water count 0

write single block mode enabled

write scsi pass-through mode enabled

read single block mode disabled

read scsi pass-through mode disabled

[NotApplicable]

Looks like I got this resolved, through working the issue. I must admit that it took a few days and the loss of a proper backup in the interim did put my client at risk to a degree, however I did try to compensate for this. The good thing is that I even trimmed a couple of hours off the backup.

Call this a moderated forum ? I certainly do not. I spend a lot of money with Symantec, Symantec AV Mail Security Backup Exec etc

I called Symantec, explained the situation to them but all they cherished was their $89 which they did not get. I will spend this ten fold with them in 3 months alone. Its a shame, you create an application and push it to the point where it is a market leader. You then have end users rely on this for business continuity and thats where your responsibilty as a vendor ends? I do not expect everyone to agree with me, its just I feel very disapointed in the experience I have received from Symantec and the worse part is that its 8.06 in the monring right now and by close of business I would have sold more Symantec products. Whos the fool? LOL

[Ken_Putnam]

write single block mode enabled

This is probably the culprit. With this enabled, all buffering is ignored/disabled. So backup exec reads a block from disk, writes it to tape, reads a block, writes it , etc

Block and buffer should be OK.  I'd probably go with a buffer of 128K, but it probably won't make much difference.

Also, shouldn'd have much effect on tghroughput, but pass thru should be disabled for locally connected devices