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I'm having trouble with ESXi backup/restore performance.

My setup:

  • VMWare ESXi 5.0.0 on a HP ProLiant DL 360 G6, runnnig RAID 5 on a P410 SmartArray as SAS
  • QNAP Nas (QNAP TS-809U-RP NAS 8 bays 4USB) Connected over Gigabit

I try to copy a 200 GB file from the NAS to the Datastore. Currently, it will take 10 hours, so the speed is about 5 MB/s. This is very slow and I'm currently trying to figure out why it is this slow.

  1. I ran esxtop on my ESXi machine, it shows mainly an idle process,
  2. I ran the QNAP system resource monitor, it shows bandwith usage of +- 10 MB/s, no real CPU usage..
  3. So it seems the ESXi server is limiting the transfer speeds somehow. Another hint for this is that the performance -> disk graph stays almost exactly on 15MB/s

What is the preferred way to find out what is limiting the speeds?


I copy the file through the UI (vSphere Client), right click the datastore, click 'copy', and in the other datastore 'paste'

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migrated from Aug 29 '12 at 12:50

This question came from our site for professional and enthusiast programmers.

This is not a programming question, and belongs in ServerFault instead. – PhonicUK Aug 29 '12 at 10:04
Flagged for request to move. Thanks for the comment btw. – RobAu Aug 29 '12 at 10:19

The fastest way to accomplish this transfer would be to use a higher-level tool like VMWare vCenter Converter to perform the migration. How are you running the copy? Drag-and-drop? Unix cp from the console?

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See edit for copy mechanism – RobAu Aug 29 '12 at 15:41
@RobAu Try using the vCenter converter I linked. Or if you have local space available, consider the OVF export method detailed here. – ewwhite Aug 29 '12 at 15:54

ESXi is not a general purpose operating system and the management login mechanism you're using is a very-low-priority process not designed to be used in the way you are doing, it will also be 'going away' at some point in the future.

So basically use the interfaces/APIs that are designed for these purposes instead of pretending it's Linux and showhorning your own solution into place.

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Check your P410 raid controller write cache. Vmware rely on hardware for caching.
You may need to add a BBU (Battery Backed Unit) on your controler to handle write back safely in case of power outtage.

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