Slow backups to Tape but fast to DiskFolder

[borainea]

Hi,

I've noticed that when I run my backup job to tape (LTO2) it runs at a speed of 133mb/min from a remote server, but when i run the exact same backup job to a disk folder it runs at a speed of well over 1000mb/min.

The backup server is a Dell Optiplex 330, Windows XP SP2, Adaptec SCSI Card and 1GB Network card, BE 9.1

The Backup Tape device is a Dell Powervault 132T

What could be causing the speed to diminish?

Originally the Backup server was a Dell Power Edge 4600 with the Adaptec SCI Card in it, the SCSI card was then just added to the Optiplex 330.

My speeds for the original backup server to a tape was in the 700mb/min range, to a disk folder it runs at round about the same as 1000mb/min

Block Size - 64k

Buffer Size - 256k (was originally 64k)

Read Single Block Mode - unchecked

Write Single Block Mode - unchecked

Read SCSI pass-through mode - unchecked

Write SCSI pass-through mode - unchecked

Would anyone beable to assist me with my problem?

[Ken_Putnam]

Are you using Symantec drivers or manufacturer drivers for the tape drive?

if you shut down all BackupExec services, does NTBackup also run slowly?

have you checked cables and terminators?  How many soft and hard write errors are reported during a backup job?

[borainea]

Hi Ken,

The tape drive is using the veritas drivers

The NTBackup runs at optimal speeds when the BE services are stopped

I'm not sure what to check on the cables or SCSI card, the card came from the original backup server and nothing really got added or removed from the physical card itself.

Whats strange is i've put the card back in the original backup server that was running at high speeds and now the speeds have dropped as it has on the new backup server - frustrating....

The only errors reported are when i canncel a job for taking too long.

[Ken_Putnam]

I was suggesting that you verify that all cables and terminators are fully seated, but if NTBack flew right along, that's probably not a problem

If you have another SCSI card, you  might try that, as you get the same slowness when putting the original back in the old server

[HAMZAOUI_Omar]

Hi,

Be sure that Removable storage service is disabled.

Best regards

[borainea]

Hi,

Removable Storage is disabled.

I've replaced the SCSI cable;

The Original backup server is running back to its usual fast speed - great

The New backup server continues to run at a 130mb/min.

I've noticed that the original backp server came out with a scsi controller, and the new backup server does not have any - would this make a difference in backup speeds?

[riva11]

I had the same problem in the past, there was a very slow trasfer rate and run a full backup was really time frustrating. The solution was easy, after a check in the Hardware Drivers, I updated the LTO tape device driver with the lastest device driver released by the manufacturer.

[CraigV]

What drivers are you using for your SCSI card? I noticed on 1 of my backup servers that when we installed a new card, Windows Server 2003 picked it up no problems, and even installed drivers for it. And that's where the problems started. If backups weren't starting, they were, but at 20MB/min, and dying a slow death as a result.
Downloading the latest drivers for the for the SCSI card from HP's website sorted out the problem.
What I can gather from your last post though is that your new server doesn't have a SCSI card, so I am assuming it's connected to the same controller as your drives are? I know for a fact that HP doesn't support this configuration, and I am not sure about Dell. It would mean your backup device is running as slow as the drives are, and will slow them down as it uses bus speed. It ends up in a vicious cycle.