ESXi

Whenever datastore is approx full then vm's are suspended but how it can create vmss file at that time if no more free space is left.

If the datastore runs out of space, the VM's which request additional disk space are "paused" rather than "suspended", so you shouldn't see a .vmss file for them.

André

Yes, I agree with "Andre". VM gets paused. Yesterday itself I came across this.

and what will happen if datastore capacity is increased and you are trying to resume the VM will you get the same memory state of the VM or not?

Yes, once VM is paused, it gives one warning "free up some disk space in order to continue". Once you free up some disk space, we have one option their on warning to retry. Once you click on "retry" vm gets started from the state where it was earlier( including memory state). I have not seen any issues. Once I had faced this problem on important domain controller, we free up some space and it worked just fine.

but from where it will get memory state without keeping any file in datastore like .vmss?

The .vmss file is only used in case of a suspended VM. For a paused VM the memory state is kept in the currently used physical memory, i.e. the active memory is not released unless you either click Cancel or reboot the host.

André

When a VM is paused, all I/O is stopped and it's state is kept as is (i.e. in memory), and you will have the option to either free up some disk space to resume (Retry) the VM or just "kill" (Cancel) it.

André

I have been fire fighting space issues last couple until new budget for more storage is approved, and I can tell you this is a pain to deal with...resuming vms, I inherited environment with attitude :smileyhappy:  never run thin on thin, you can easily over-provision and shoot yourself in the foot.