Failed to create snapshot for VMx, error -3941 ( create snapshot failed)

[kopper27]

hi guys

Right now I have two destinations  both are virtual disk:

250GB from SAN added as a Hard Disk to the vDR

350GB from NFS(external server with NFS enabled) added as a Hard Disk to the vDR

I tested both destinations with VMs around 40GB and they work OK.

but I basically need to backup a Big Hard Disk 350GB only 200GB spaced used.

The backups works OK in the 250GB Hard Disk from SAN

but it fails with error Failed to create snapshot for VMx, error -3941 ( create snapshot failed) just a few  seconds after I start the Backup Job

when trying to backup this vmdk to the NFS

Any idea what could be wrong? NFS issue or something related?

vDR already rebooted and turned off. Same issue

thanks a lot guys

[a_p_]

Take a look at http://kb.vmware.com/kb/1028924

What is the block size of the VMFS datastore on which the VM you want to backup is located?

André

PS: Are you able to create a snapshot on this VM manually?

[kopper27]

a.p thanks

The datastore that fails for the backup is an NFS from a Linux physical Machine so there is no block size to define.

the datastore that works ok for backups is 8 MB anyway

like I said when doing backups to the normal SAN DataStore (virtual disk 250GB) works OK.

but it won't do it when the backup uses NFS as a destination for this VMDK.

Other VMs I've tested work ok they are around 40GB and backup OK on this NFS destination.

[a_p_]

Just for me to fully understand. Is the whole VM (vmx, vmdk, nvram, ...) located on the NFS or is it just the virtual disk (vmdk) and the VM's base folder is located on a VMFS volume?

André

[cor_-_ORTEC]

Have you checked the vmware.log file of the virtual machine, you should see a number of errors related to the failed snapshot that should point you in teh right directions.

As responded previously, block size might be a factor, but since all our VM's and Drives reside on Hosts running the VMWare platform not sure how this works in your situation.

RGDS

Cor

[kopper27]

sorry I was not clear.

This is VM I am trying to backup which is a in DataStore DataStore1 based on FC SAN block size 8

VM1 has 3 VMDKs

VMDK1

VMDK2

VMDK3

vDR has 2 destinations:

One is located in the same FC SAN and was added as local Hard Disk 250GB.

Second destination is 350GB NFS Based (linux machine) vDR in order to use NFS as destination the NFS Share must be added to the ESX and after that I created a 350GB Hard Disk for vDR.

Cool.

Now

I am trying to backup VMDK3 which is 300GB VMKD and 200 space used.

Destination 1 backup job works OK.

Destination 1 backup fails with the error mentioned

Weird thing is backing up ather VMs with just one VMDK aroung 40GB works OK on this NFS destination.

thanks

[kopper27]

just to let you know guys

I just did some more test backups of little VMs and tired of this I executed the backup for the Big VMDK to the NFS Destination now is working 3% I will let you know the results in some hours

[petedr]

The 3941 snapshot error I believe is reference to vmfs blocksize as was posted in the KB article in this thread. Could it be your vDR appliance is on a vmfs with a 1 MB block size.

www.thevirtualheadline.com

[kopper27]

yeah vDR is on ESXi localstorage 1MB but the destinations are on 8 MB and NFS

[petedr]

That is probably it, vDR being on a vmfs with a 1 MB blocksize.

www.thevirtualheadline.com