Slow Backup with IBM HH LTO Gen 3 Tape Drive

[Aptus]

I've installed 11d along with the Veritas driver for an IBM HH LTO3 tape drive on Server 2003 R2. I can backup but the job rate is 27mb/min wirh 49gb taking 29hours! If I uninstall the driver and use windows backup with the ibm driver the job takes 41minutes. I've tried vaious block sizes but no difference. I can't get veritas to see the drive unless I use the Veritas driver.

Any ideas? - Thanks

[Ken_Putnam]

If you are using the Symanatec driver, make sure that Single Block Write is NOT selected

Try loading the mfg driver, then run TAPEINST and tell it to use existing drivers

[Craig_S1]

Is this problem still evident after applying hotfix 29?

[Aptus]

Still no improvement. Single write block not selected and Hotfix 29 installed. I was able to get Backup exec to see the drive with the manufacturers driver after running tapeinst, but still get only 26mb/min.

Thanks for your help and please keep the ideas coming.

[Craig_S1]

Have you tried the latest Backupexec DDI pack? It's available from: http://seer.entsupport.symantec.com/docs/294731.htm - let us know how you get on.

[Aptus]

Hi Craig,

I've got the latest DDI pack installed and other ideas?

Thanks for you help.

[Ben_L_]

What speeds do you get with the Vendor driver and Backup Exec?  It is not a requirement to use the Symantec drivers for you devices, only a recommendation.

[Aptus]

I get around 27mb/min with both the Veritas driver and the vendor driver when using Backup exec. If I use windows backup with the vendor driver then the backup tales about 40 minutes rahter than the 29 hours Backup exec currently takes.

Shall I pin my hopes on Backup exec 12?

[Hywel_Mallett]

Is this a SCSI drive? I have seen similar symptoms when a drive was cabled incorrectly. In the case I saw, the drive had a SCSI in and SCSI out port, and the cable was connected to the wrong port.

I've also had systems where the default SCSI adapter card settings need to be changed in order to get the optimum performance.

[Aptus]

It doesn't appear to be a hardware problem as the backup flies with windows backup. Thought I'd try upgrading to version 12, got rather excited when during the installation it recognised the drive and said it was supported. Still only get 27mb/min though. Despair is setting in...

[Aptus]

I've found that by changing the drive properties to Block Size 64kb, Buffer Size 512kb, Buffer Count 10, High Water Count 7, the job rate has increase to 1,368 mb/min. I'm pleased with this rather marked improvement but just wondered if there are any official / recommended settings out there?

[Ken_Putnam]

What were the settings before?

The block size should always be the largest supported by you device, and you should have enough buffer space (combination  fo size and number) so that BackupExec never has to wait for the buffers to re-fill

64/512/10 sounds like a good setting.  if you want to really play with it, you could try decreasing either number or size and see if the speed drops off, or expanding even more to see if the speeds go up any more

Officially the response from Symantec is going to be either "leave the settings at the default for your device" (and we've see how that works.  Early in v11d, some default settings were 32/32/1 !)  or "see the manufacturer's documentation for specific settings"

[John_Kerkhofs]

I'm having exactly this problem as well.  IBM x3650 Server, HH LTO 3 SAS tape drive, Backup Exec 12.  Latest drivers for everything, tried both IBM and Symantec tape drivers.  The default settings  run a backup at 26 MB/Min, and adjusting the block size, buffers etc can get the speed up to 1090 MB/Min.  Two problems, though - If the BEX services are restarted, the drive settings revert to default.  The second and more serious problem is that when backing up a remote server using the agent the job always fails with these errors:

Final error: 0xe000fe30 - A communications failure has occurred.
Final error category: Server Errors

V-79-57344-65072 - The connection to target system has been lost. Backup set canceled.

I've been through the technotes, tried changing the agent priority, checked all the network drivers.  The job runs fine until the last file, then fails. 

Any suggestions? 

[amit-TCs]

go in backup exec remote agent registry and change the chnage journel value to 0 from 1 and restart teh services.

will fix the issue.