Why do Virtual machines are inaccessible after change in datastore?

[Chandrashekhar]

Hi,

I have two ESX 3.5 servers running which share two SAN disks. I have moved VM files of all the VM's from one SAN disk to another SAN disk using vCenter server. After moving these files, i am unable to work with virtual machines (Cannot start virtual machines). I have restarted one ESX server after moving VM files. In vCenter server, I can see that VM's are inaccessible. I have attached screen shot of the vCenter client application.

For other ESX server (which I have not re started after moving VM files) VM is accessible, but if I try to start that VM, I get an error saying

*"A general system error occured : The system returned an error. Communication with VM may have been interupted."*

I am attaching the screen shot of this error also.

When I installed ESX on server for first time, I had created virtual machines on hard disk of ESX server only. After that, I moved VM files from ESX hard disk to shared SAN disk.

Does anyone knows what is the problem?

[Texiwill]

Hello,

How are you moving the VMs from datastore to datastore? are you using SVMotion? If so do your VMs have snapshots? If so that is the general culprit.

Best regards,

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[anujmodi1 · Accepted solution]

Inaccessible VM can be due to different reasons. So it depends how you migrated the VM between datastore. If vmx or vmdk files are not accessible from storage then you see this error message. Otherwise check that all the files in VM has been moved to single datastore and there is no delta file left behind. this happen if migration is not complete.

If you see some delta file there, then clone a new vmdk with "vmkfstools -i" switch and attach with VM and try to power on.

Anuj Modi,

If you found my answer to be useful, feel free to mark it as Helpful or Correct.

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[Chandrashekhar]

Thanks for clue. I had moved VM files from hard disk of ESX server to SAN disk using vCenter client only. As you said, the problem was with delta file only. I had to remove all the VM's and re create virtual machines again. As entire setup was experimental, it was not a big problem.

One stupid question - how to mark your answer as "Correct" ? I cant c any button or link for it !!!