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zpUIU52b4
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Copying large thin-provisioned VMDKs from NAS to ESXi 5.5 DAS extremely slow

Hi everyone.

I'm hoping you can help with an issue we are having.

We are using a ReadyNAS Pro 4 as off-line backup of VMs and to move VMs between 2 sites. Running RAIDiator 4.2.26 and ESXi 5.5. Using NFS. We copied a bunch of VMs to the NAS at site 1. Sent it to site 2. Using Datastore Browser in VMWare we can copy anything off the NAS to ESXi's direct attached storage and vice versa.

The problem we are currently having is that the NAS copies are slow when it comes to copying a thin provisioned VMDK from the NAS over NFS to DAS.

It's a thin provisioned VMDK which is 40GB. The files size has reached 40GB and it's not growing so it's not inflating the drive to a thick VMDK. The problem is the copy time is slowwwww at 2000+ hours.

Is this expected? Has anyone come across this before? 

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a_p_
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I would have expected 5000+ hours Smiley Wink. Just kidding.

There's got to be either a network or storage issue which is causing the huge copy time. Even with a 100 MBit/s connection it shouldn't require much more than 1-2 hours.

Take a look at the vmkernel log (e.g. by pressing "F12" on the console) to see whether this gives you any hints.

André

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