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Why is my SAN/Restore so slow?

hongedit asked
Last Modified: 2012-08-14
Hi all

Last night I made a massive mistake and managed to delete the 2 vmdk's containing my Exchange Mailboxes and Logs.

Never fear, for I had done a full backup of the VMDK's earlier that day with VMWare Data Recovery.

At 2:30am it had completed 20%. Its now 13:45 the next day and its still on only. 75%

Monitoring the SAN using Resource Monitor, I can see Disk I/O is sitting at around 5-10MB/sec. Network Utilisation is around 100-120Mbps.

This was done on a bit of a budget as detailed below but it still should not be this slow in my opinion. Where is my bottleneck?

THe iSCSI SAN Disks are NL SATA disks. Yes I know, but still should not be this slow?

There are 5 1Gb links going into the SAN Switch (seperate network to Data), but only 1 of these are operational as I messed up the Link Teaming (chose wrong type).

Could it be this? Surely if this was maxing out, it'd be at 90%+ utilisation?

The disks are 4 NL SAS (SATA) disks in Raid 5 or 6 (cant rememebr which, and I cant access the concole right now).

Using DiskSpeed, the Max Read speed is clocked at 229.82MB/sec. Which is miles from 5-10MB/sec its operating at for this restore.

The Data network (which is the VM Management and Client Access network) is only 100Mbps (this will change to a GB Switch later this week), but I dont think the restore needs to even touch the data network?

Where is my bottleneck?

I'll see if I can knock up a quick diagram.
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