Backup Speed slowdown

[acl03]

We were having lots of issues with failed backups, so we broke down and made a few upgrades:

Replaced all cables/terminators
Replaced server
Upgraded from BE 9.1 to BE 11d
Replaced SCSI Card

We are using an HP MSL5026 tape library with 2 Compaq 100/200 GB SDLT Tape Drives.

The job rate for our old server was a little over 1GB/sec (on the drive that had compression turned on). I had a big job (1.2 TB) this weekend, and it only ran at 340MB/min.

I have since turned on compression on for both drives, with the help from

http://www.tek-tips.com/viewthread.cfm?qid=1447397&page=1,

and was hoping to see the 1gb/sec performance and then some with the new system.

I do not know too much about SCSI setup, but I suspect maybe some settings on the new SCSI card are not set up optimally.

The old scsi card was listed in device manager as:
LSI Adapter, Ultra320 SCSI 2000 Series (w/1020/1030)(StorPort)

The new scsi card is listed as:
LSI Logic PCI-X Ultra320 SCSU Host Adapter

I have not modified any scsi settings in the bios (I assume there are some I can change). I know that the new scsi card uses the same cables as the old one. Shouldn't the throughput be the same?

Not sure if I have SCSI or BackupExec (or both) options that I should look at. Any help would be greatly appreciated.



Thanks,
Andrew

 

[DTracy]

You might try swaping drivers, ie: if you are using HP drivers for the tape, try the Veratas, or vise-versa.

I would make a small test backup job that uses the same file as was used with the old system, that way you will be able to more accurately gauge the throughput rate. ie: myfile.txt on the old system backs up at say 500 mb/sec, what does it do on the new? This assumes you still have some of the old backup logs.

There are many things that will effect throughput speed, check the KB for a list.

Regards,
David.

 

[acl03]

I could boot the old server and take a look at some logs. I have a small test job that I used to run on the old server, (backs up about 240 megs) and i seem to recall it backing up around 1gb/sec.

I ran the same job on the new setup and got the slow 340mb/sec speed. Wouldn't a big job that backs up many different types of files be a more accurate speed guage?



Thanks,
Andrew

 

[acl03]

Also, the verify from our big job is still running at about 1.3GB/sec - maybe that gives some sort of clue?



Thanks,
Andrew

 

[DTracy]

Well, verify runs faster anyway because it's not writing data just checking catalog (if so configured) and checksum.

Are you backing up across a LAN--multiple data servers and such? How did the configuration pre-test for 11d turn out, were there any potential problems spotted? Are you running remote agents? AOFO? SQL?

There are a lot of possibilities, try the drivers first, and read the KB articles on helping the throughput speed.

David.

 

[acl03]

Ok, I'll check out the KB and drivers. I have heard that it is always better to use Veritas drivers as opposed to windows drivers, so that's what I'm doing for now.


We are backing up over a lan, just 1 server. It is using just AOFO.

The pre-test on the 11d installation was perfect, no issues at all, green checks all the way down.



Thanks,
Andrew

 

[DTracy]

Over the weekend our system did a full backup, and duplication. The backup was to disk @ 325 MB/min. The duplication was to tape @ 4039 MB/min (67.32 MB/sec). I looked back through the log and this seems to be about average for both jobs.

We have BE 11d 64 bit on a Dell 2950 64 bit server and a Dell PowerVault 132 tape library (SCSI). It uses those LTO3 tapes 200/400 GB.

This thing runs pretty good for it's size and value.

David.

 

[acl03]

That's amazing tape speed. As I am new to this, I assume LTO3 tapes are used by much faster drives than our DLT I tapes, right?

Do you know what kind of speed I should expect from my tape system, if all things were set up correctly?



Thanks,
Andrew

 

[DTracy]

I don't have any personal information on your particular tape drive, perhaps someone else could interject. But, our tape drive gets busy. It seems like it takes longer to load the tape from the library than anything else. We have DAT systems in other parts of the county and they aren't as fast as the LTO3.

David.