12-13-2010 06:37 AM
Hi,
we backup our SAN-System (EMC Clariion, FC, Hyper-V Files) and NAS (QNAP, Gigabit-Network, large image files) with a fc-connected tape library Quantum Scalar 50 (LTO3) and Backup Exec 2010 R2.
The SAN-based part of the backup job is fast, the NAS-based is not. The average throughput from NAS to Tape is <40MB/s, but the verification with same components the average througput is >70MB/s. What's the reason for this difference?
Thank you.
Erik
12-13-2010 08:59 AM
Verification verifies the data written to your backup TARGET, and does not compare the SOURCE data. Thus, the speeds will never match up.
Also, since you are backing up a NAS, it's typically a slower throughput (e.g. 1Gb vs 2/4GB FC) so that is also why you are seeing the slowdown in backup throughput.