Backup to disk very slow

[zanshin]

Hi,

I did several tests with backup to disk and Symantec Backup Exec 2010 R2 and R3.

We're using a Windows Server 2003 as a mediaserver and a Dell TL2000 with LTO3 for tape backup.

Now I want to implement a backup-to-disk-to-tape strategy but I can't do this with this bad performance.

The backup to disk folder is on a Equallogic PS5000 and the mediaserver is connected with two interfaces and MPIO enabled.

The disk performance is very good.

HD Speed reports about 170 MB/sec and Iometer reports about 220 MB/sec !!!!

When I backup data from a local drive of the mediaserver I get rates about 3000-4000 MB/min to tape. But when I start the same job to the backup to disk folder, I only get about 1500 MB/min. I also tested the jobs with a formated/unfragmented volume for the backup to disk and with a backup to disk folder on a local driver (not iSCSI) .... same issue. Of course the behavior is the same when I backup remote agents.

I ran several concurrent jobs and it seems that the thruput of about 1500 MB/min is shared between all jobs.

When the backup to disk is running, the iSCSI interfaces of the mediaserver have only a 20% workload and when I start a benchmark tool (Iometer or HD Speed) the workload goes up to about 90% durring the backup. So this shows that the iSCSI network and the iSCSI storage has enough performace resources and everything on the iSCSI site is correct configured.

Seems that Backup Exec puts a limitiation on the backup to disk processes.

Any ideas? Thanks!

[Matthew_Frahm]

I, too, see disappointing performance SOMETIMES combining Backup Exec and my EqualLogic environment. 

Using Advanced Disk-Based Option, I actually get half or 2/3 of the speed I get if I don't use ADBO. 

I don't understand why since these backups are the only substantial activity at that time, there's one NIC connected, I can run SQLIO from my Backup Exec server on an iSCSI volume created specifically for the test and meet the benchmark performance I'm supposed to attain.  It seems to be an application issue.

[teiva-boy]

Try multiple conncurrent jobs.  A single job will not leverage your MPIO features, as a single job is a single connection/stream.  MPIO works only on new connections/streams for all applications.

Try a larger NTFS allocation unit size

Format using larger blocks

Try Jumbo Frames

Do each of the above changes individually to verify a change in performance