Snapshot very slow on power-on, Snapshot very fast on power-off. Why ?

[luicst]

I installed MS-Windows on vSphere VM.

If MS-Windows VM is running, Snapshot is very slow, it spend 7 minutes.

If MS-Windows VM is power-off, Snapshot is very fast, it spend <= 5 seconds.

Why ?

How to improve ?

Thank you very much.

[mpverr]

Not much to go on here, BUT....

When you do the snapshot with the VM on, do you also select to "snapshot the memory"?

If so, the larger the memory, the longer it can take to snapshot.

I"m going to also guess you have a pretty slow disk subsystem if it is taking 7 minutes. You need more I/O - is this on stand alone host and not on a san?

[AndreTheGiant]

For a powered on VM also without the "snapshot the memory" there is an addition delay caused by the temporally quiescence operation on the disk (to permit the snapshot).

Andre