VMware ESXi 4.10 8 CPU cores (Xeon E5506)/24GB RAM/local RAID volume/Multiple SAN volumes

I have a problem with very slow file transfers on a VMWare ESXi host. Using a 200MB test file:

Using Guest OS (underlaying datastore on SAN) Copy over network to local drive: 15 seconds Copy within the guest OS: 5 seconds

Using Host (ssh to server, similar results for Vreem backup and Datastore Explorer) Copy from Local array to local array: 60 seconds Copy from Local array to SAN volume: 35 seconds Copy from SAN volume to same SAN volume: 29 seconds Copy from one SAN volume to another: 47 seconds

This is causing problems because I need to move a virtual machine to a new datastore for space reasons, but the filecopy will take over 24 hours which is too long an outage window.

Does anyone have any advice on how to get better filecopy performance from the Vsphere host? It's not a SAN specific issue because even a copy within the local array is very slow, and the guest OS performance is much faster.


SSH/SCP speeds are throttled in ESXi 4. I don't recall if it's an encryption issue in BusyBox or not.

Some have tried FTP with success, as it's not capped.

Using the vSphere Converter is another option.

But if you have both datastores mounted to the ESXi host, can't you perform a "Migrate", or do I not fully understand your infrastructure design?

  • Migrate is a function of vCenter, which we don't have for this office. I just checked our datacentre vCenter and it's not possible to migrate storage to a new datastore on a running VM without a Storage vMotion license. – DrStalker Jul 5 '12 at 22:40
  • But you can migrate a powered-down VM without svMotion. – ewwhite Jul 5 '12 at 22:44

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