Throughput issues.

[tEkHEd]

Hi there..

Has anyone ever had any throughput issues with Backup Exec?

I have a Win2K server with Backup Exec driving either HP-818's or Quantum 8000 tape devices.

These are connected via a fast SCSI buss (Adaptec 39160/3960D Ultra 160)

I am currently getting around 300 - 350 Mb/Min as a transfer rate in the activity monitor.

This is causing a huge issue as the backup jobs are overrunning etc...

does anyone have any ideas of other things to check?

I have done the usual:

SCSI drivers
SCSI BIOS
Checked Network settings (1Gb/s Full Duplex)

Backup Exec Ver: 8.60

There doesn't seem to be any pattern as to when/why this is happening.. I am gettting the same issue on several devices/servers with differing hardware, but similar configs.

Any help is gratefully recieved.. cheers

 

[JohnCitron]

I have had a similar throughput problem after upgrading to an HP-Surestore 8000 (DLT8000) from an HP-Surestore 4000. Overall, the drive operates slower than the old one, and that seems to have thrown a curve in my backup time.

What kind of tape drive were you using prior to this one?

John

 

[tEkHEd]

sorry I don't know the answer to that.. all I know is that we are currently using a mixture of HP 818/8000 autoloader, each with DLT8000 tapes.

I have upgraded the Adaptec 39160 BIOS to v3.1, and the drivers are v6.128. It is very strange as I have 2 818's on their own channel on the adaptec card, and 1 is now backin up @ 147Mb/m and the other is right down to 30Mb/m..

I am begining to think that it is an issue with the hardware combination of:

Dell Poweredge 2650
HP Autoloader (818/8000)
Adaptec 39160


We have some older compaq servers with Adaptec 2940's in and these are backin up fine @ 360Mb/m +

 

[slcengineer]

I also have a Poweredge 2650. I use it with a Qualstar library and 2 Sony AIT2 drives. I am lucky if i get better than 180 MB throughput. I have been working with Qualstar on and off since April. They even sent me new drives. the only thing left was the server (with 29160 LP's)(I also replaced these). I am left with it being either the server
or Veritas (8.6)

 

[jbud]

If the 39160 will let you (I'm pretty certain it will), you may want to disable domain validation and individually specify the bus speed to each SCSI id.

Adaptec tech support did an excellent job of talking me through this. I've just set up a 29160 with new SDLTs, and, in troubleshooting, I was able to slow down the bus to the individual tape drive's ID. You may want to do this if all of the devices on the bus are going to use the same speed.

 

[tEkHEd]

Hi Jbud/slcengineer..

I phoned up Dell and they directed me to a new BIOS for the poweredge (A16) and they also have a new drvier version for the 39160 v6.1.XXX.X (sorry not at work and can't remember the full rls)..

I had also tried disabling the Domain Validation, along with setting the SCSI bus to 10Mb/s, as that was a solution given for Netware servers experiencing the same issue..

Before the updates this had no effect what-so-ever

After the updates I got nominal speeds of ~250Mb/M with the 818's attached but found that with 2x 818's attached, 1 would invariably be slower than the other.. v strange. I ended up putting an 818 and an 8000 on seperate channels and got speeds of ~ 300Mb/M on both devices.

I then reset the Domain Validation and the SCSI bus to defaults and still maintained those speeds..

I can't say for definate if it was the Bios update or the driver update from Dell that did it as I applied both at the same time, but the combination of both definately helped.

thanks for ur input