Backup Exec 12.5 and HP MSL4048

[EBK]

Hi

Is there anyone who has some experience with optimizing the configuration for the HP MSL4048?

Block size
Buffer size
Buffer count
High water count

The backup jobs seem to be taking longer that they should. We are backing up virtual machines using AVVI. The throughput is 1.5GB/min which seems slow for a 4GB FC network...

Thanks

[CraigV]

If all your servers are on that SAN, then it is too slow. If not and you're backing across your LAN, that's where the slow-down is occurring. I normally up my Buffer Size on the HP StorageWorks 1/8 autoloaders we have, but will do the same with the MSL2024s we're using.
We have an MSL6060 at our Head Office, and the Buffer Size is 1MB. I don't touch any other settings.

[EBK]

Hi
Thanks for your reply.
I have upgraded the block size to 512K and buffer size to 512K without seeing a major difference so far. I will push the buffer size to 1M and see how it goes.
Within the backup job setup, I selected "SAN - Backup virtual disk that resides on a shared fiber channel or an ISCSI storage" so I don't think I am backing up accross the LAN.

I will keep you posted.

[travesty]

I'm very interested in your findings EBK because we basically have the same setup and we use a MSL4048.  Our disk to tape backups run between 1GB/min - 2GB/min and I haven't been able to figure out anything to make them run faster.  Keep us posted.

[CraigV]

Don't change your block size without making sure that you can restore properly. THere is a post somewhere in the forum where a guy changed the block size and couldn't restore.
The thing with the SAN SSO is that to make proper use of the SAN, you need to have a full version of Backup Exec installed on a SAN SSO server. THere is a central one which shares the library, and the distributed servers see that library. If they have SAN disks (like on an EVA or Clarion for example), they backup across the SAN back-bone. Otherwise you use the normal agent which uses the LAN.

[EBK]

Hi

I thought I'd drop an update here as it has been ages... it looks like we can't go above 2.200 MB/min. I have actived the VCB compression and disabled GRT.

I have also changed the block size to 512K and buffer size to 1M which is the max offered. It did help a little bit but not massivly. 

I kind of think, it depends how you zone the tape library and the backup server. We have added a second HBA card and that did help too. 

 Not sure if anyone managed to improve their backup job elsewhere??