hi,

We have here kvm.


The source host and the target host see the disk where VM resides,see the same nfs or cifs exported share.
Is it safe to move a VM (with linux that has nfs or cifs shared mounted inside VM) to other host?

Is it safe to move a VM that is very high loaded to other host?either the i/o traffic is very high or the cpus are very loaded.

if there inside VM is high i/o traffic can be a delay in moving the VM to other host?

In general: you can move a VM only when it is off (otherwise should be safe).

(by the way what do you mean by moving a VM?)

Libvirt supports live migration. The VM is running while its memory is being copied over. It can even switch over to the destination host before all its pages are copied (they will then be page-faulted from the source). Incredible but true. I've seen it happen

Intensive memory writes can slow live migration down. If RAM accesses are faster than page copies, the VM might even never migrate.
If the VM's storage is not shared between source and destination host, it must also be copied, and in this situation, I imagine intensive disk writes might have the same delaying effect as RAM writes. However you mention NFS or CIFS, so I doubt this is a problem for you.

Also, CPU load is irrelevant. The VM initially uses the source host's CPU, and at some point it is stopped for a fraction of a second and switched-on on the destination host. That's all.