backup very slow for some VMWare

[pruvn]

Hi all,

We are facing a difficult issue for now, that is some of our VM(VMWare) backed up by Symantec NBU v7 is very slow compared with other ones. The best thruput can be up to 60MB/s, whilst some other VM is only 4 to 5 MBbs. FYI, we only have 1 policy for VM and applied for all VM, and all VM is stored on EMC SAN ClariiON CX4.

Via bptm log it seems the slow VM are busy at that time as bptm had to wait to fill in the buffer, but actually can't know what is the different betweens the VMs.

 22:49:48.429 [6388.6392] <2> write_data: waited for full buffer 987 times, delayed 7222 times
 23:29:29.277 [2248.5160] <2> write_data: waited for full buffer 15622 times, delayed 142310 times

Look forward to hearing from you all.

Regards,

Khanh

[Dataway]

how you are backing up the clariion? NDMP or presenting snapshots to the NBU server?

[Ronald4063]

are the slow vm's on a different LUN (e.g. SATA/LUN) than those which are running normal?

did you try moving a slow machine to a different LUN?

[teiva-boy]

You should also get a NAR file from teh clariion, and send it your EMC SE.  He can track the performance of your clariion to make sure you don't have any hotspots on your SAN.

Your backup is only as good as your infrastructure, and backup apps do a great job of showing you where you have bottlenecks!