PowerVault 120T DLT1 Autoloader SLOW

I have a Dell PowerVault 120T DLT1 Autoloader that has consistently backed up at a rate between 40mb/min and 80mb/min ever since we got it via warranty replacement. We've been able to deal with the slow speed since we weren't backing up that much, but now our situation has changed and I require more speed. How can I make it backup faster?

Situation: Windows 2000 Server on Dell PowerEdge 2650 (4V4D631) with an added SCSI card Adaptec SCSI 39160, which was purchased from Dell with the PowerVault 120T DLT1 Autoloader (J3TZH01). We are using Veritas BackupExec 8.6 with the Veritas Tape Drivers.

We have already tried: We have run this backup device from three different servers, of course each time using the same SCSI Card, which is not running any other device. We have loaded different Veritas drivers until their tech support has given up on us. We have tried different backup jobs, both local server and remote server. On one server Dell PowerEdge 2200 we even used the NTBackup that comes with Windows2000. We got the same results.

I read a post on this forum where a similar Dell PowerVault is actually a Sony model. Could I benefit by using Sony drivers with this PowerVault? Could this just be a dud machine from the start? Any help would be appreciated!

Responses(3)

DR

dell-richard g

605 Posts

0

February 11th, 2004 01:00

The DLT1 drive should give you rates from 3 MB/Sec - 6 MB/Sec (180 MB/Min - 360 MB/Min). The 40-80 MB/Min you are seeing seems very slow.

Make sure that you clean the drive head.

Use the latest Veritas tape class drivers from the Veritas website. Also, rerun the Veritas device detection program so that it reloads the driver. Make sure that the block size for the drive is set to 32K (you can right click on the drive via the Backup Exec GUI).

The DLT1 drive is not Sony, it is a Quantum drive. The Veritas tape class drivers are already optimized, so no need to install the Quantum version of the drivers. If you file system is very "busy", this will impact read performance from the source disk when doing backups.

Also, if you are backign up many (thousands) small files, this will cause backups to perform slowly.

R

RiversideKid

27 Posts

0

February 11th, 2004 09:00

Thanks for the reply.

Clean: We clean the drive head weekly, I know it's "too often" but otherwise we get CRC errors on almost every tape (even brand new tapes that work fine in our other backup unit a Dell PV122T.)

Drivers: We have loaded and reloaded the Veritas drivers with the latest from the Veritas site time and time again. We have even moved the backup unit to a new server, three servers in all have been used in attempts to gain some speed out of this unit.

Block size: We have tried many block sizes to gain some speed, of course the default (32K) is what we leave it at when we give up.

Busy: We perform the backups at night and weekends to ensure the servers are not in use when the backup is performed. (Full backup on Sunday when no one is here, and Differentials each night after all our departments close.)

File size: We have set up test jobs of large files only (Ghost images), medium files, and small files to see if that helps, but to no avail.

This backup unit is a 120T. Our other backup unit 122T is working fine and using the same drivers, has been installed in the same manner and at times even runs some of the same backup jobs with the same tapes. Personally I am convinced that it is a hardware problem, but I don't know if it's the backup unit or the SCSI card.

What else can I do to troubleshoot?

S

santonoff

1 Message

0

July 12th, 2009 15:00

I have two virtually identical units, one from ADIC one from Dell. The ADIC runs on SE SCSI, the Dell on HVD.

The ADIC unit gets 200-300MB/minute backup speed.

On the same directory, the Dell unit gets 20MB/minute. Not a type: 90% slower than the ADIC unit.

Both are locally attached, both DLT7000. The ADIC unit is attached to an Adaptec 2940U2W, the Dell 120T is attached to an Adapted 3944AUWD, on the same computer, same backup software, etc.

BackupExec 11d is the backup software. The BackupExec drivers are in use for all DLT drives (I have 5 stand-alone drives and the two autoloaders).

Any ideas why the Dell 120T is running so slowly?

View All

No Events found!