MSA Storage
cancel
Showing results for 
Search instead for 
Did you mean: 

Load Balance HBA

 
CA1149054
Occasional Contributor

Load Balance HBA

We have a MSA 1500cs with dual MSA1000 controllers. This is hooked to a 4/16 Fiber switch. I have a backup server with a SCSI attached 2024 tape library. The server is connected to the San with 2 port Emulex HBA. When backing up we are seeing 400MB to 500MB through put. Can I get this increased by load balance on the HBA, and is that even the way to go?
7 REPLIES 7
tharrold
Frequent Advisor

Re: Load Balance HBA

Mitch,

This is windows, I assume? You should look at obtaining the windows MPIO driver, so you can maximize your SAN throughput.

That being said, what are you backing up? remote servers, or local files (on your backup server)?

You may be dealing with block size limitations of your tape drives. The default block size is usually low - 64k, and for certain tape drives, such as Ultrium, you can increase this to see better throughput.

-tjh
CA1149054
Occasional Contributor

Re: Load Balance HBA

Thomas,

Yes it is windows, as for MPIO I have installed the HP MPIO but really after that I can not find anyway to modify it so if you have some directions that would be helpful. We will be backing up data, SQL, Exchange once this is all setup about 2.5 TB.

Thanks
tharrold
Frequent Advisor

Re: Load Balance HBA

If you have windows MPIO driver installed, then you should be OK from the SAN-->disk perspective. You can (and should) test multipathing, by pulling one SAN connection at a time.

From your computer management window, you can select and monitor MPIO. You should see the status degrade when you pull a SAN connection, and return to "optimal" when you replace the connection.

Now, focus on your tape drive and backup software configuration. What type of drive?
SCSI connected can be a limitation, but see if you can determine the default block size that your backup SW is using. Often default block sizes are set too low.

-tjh
CA1149054
Occasional Contributor

Re: Load Balance HBA

We have a msl2024 hooked up via scsi to backup server which is HBA to SAN. 64K is as high as Veritas 10d will let me go I did increase the buffer to 1024. Any further Ideas?

As for MPIO it is working as it is suppose to.
tharrold
Frequent Advisor

Re: Load Balance HBA

Which msl2024? You can have an Ultrium 960 or Ultrium 448 in that unit. In either case, a block size of 64k is *really* doing you a dis-service.

Make sure that it's not the O/S holding you back - windows 2003 server SP1 introduced a bug that limited block size to 64k. Microsoft created a hotfix, and it is supposed to be resolved ing SP2.

If you are limited by BackupExec, you can try contacting Symantec to see if they plan to allow >64K block sizes. We use HP's data protector, which can go to 256K block size. It made a HUGE difference in throughput to our drives.

I believe that Symantec Netbackup product will also allow you to set the block sizes much larger.

Lastly, download, and run HP's LTT (library and tape tools) to make sure you have current firmware for both the drives, and your library.

-tjh
CA1149054
Occasional Contributor

Re: Load Balance HBA

We have the Ultrium 920 SCSI drive. I will look into your suggestions.

Thanks
tharrold
Frequent Advisor

Re: Load Balance HBA

I forgot to mention: The throughput to the LTO3 (Ultrium960) varies wildly, depending on how much data you feed it.

You want as many backup streams going to the drive as possible. I'm not a backupexec guru, but most SW packages allow you to increase drive concurrency. If you can do this in Backupexec, set it to 15 or more. (I use 30 to feed a FC attached drive).

-tjh