Backup Exec 2010 Performance Very Slow

Hello,

I'm backing up Veeam Files with Symantec Backup Exec 2010 from a Repository VM that has LUNs attached as vRDM in vSphere Environment.

Nothing has been changed in my environment, and all of the sudden the backup rate went down from approximately 3GB/m to 560MB/m. This is really annoying.

Repository SAN Storage: IBM DS3512

LUN: Raid-5 7200 rpm x 11 disks.

Backup Exec: 2010 13.0 Rev 2896(64bit)

Virtual Machine: Windows 2008 R2 SP1 Enterprise

vCPU: 8 x 2.80 GHz

vRAM: 12 GB

vSphere ESXi 5.0.0,623860

LUNs are vRDM and the Mappings on different LUN.

Any help tips/ how to will be highly appreciated.

Thanks,