vm freezes ESXI 5.1 - 5.5

[fujicolor]

Dear all

We are having a problem for several months now, vm`s are freezing and cannot be connected by RDP.

The vm console does not react on crtl alt del

The only thing that sometimes works is the ping to the vm.

we have 2 clusters one 5.1 and one 5.5, we are migrating in fases.

and random in both clusters vm`s are freezing, average of 2 a week

reset the vm is a temp solution for this problem.

Aditional info: we use veeam 8  for our vm backup

is there a solution for this problem, thanks for all the reply

[DeaconZ]

Are these SQL VM's by chance or some other application that experiences heavy IO?

I am experiencing the same issue with a SQL VM that is hosting our Solarwinds Network Monitor DB. When VEEAM v9 calls the snapshot removal, the ESXi 5.5 host becomes disconnected and unresponsive. I have to reset the host to clear it which crashes all the VM's.

[ch1ta]

Is there any correlation between certain event and VM freeze? Say, snapshot consolidation or similar?

If yes, it might be worth updating directly to 6.0 as snapshot consolidation logic was drastically improved in vSphere 6.0 release.

Cheers.