These restrictions are not there due to Hypervisor limitations. These limitations are due to way this feature is implemented in CloudStack. If we allow those operation then they may work fine but in long run they may lead to corruption of VM etc. So to avoid those situation these restrictions are added till we we figure out the better way.
Regards, Anshul On 28-Apr-2015, at 3:27 pm, Jan-Arve Nygård <jan.arve.nyg...@gmail.com<mailto:jan.arve.nyg...@gmail.com>> wrote: Thanks Anshul, I did a quick test with adding vCPU and NIC in XenCenter after creating a snapshot through CloudStack. I also tried reverting the VM to the snapshots afterwards with the vCPU and NIC still added, and it worked OK. This made curious about what the background and details for this patch is. If it's specific to any hypervisor/version and maybe is fixed in XenServer 6.5? If you have some more details about why this was patched I could maybe help about with testing this with XenServer 6.5. -thinktwo 2015-04-28 10:32 GMT+02:00 Anshul Gangwar <anshul.gang...@citrix.com<mailto:anshul.gang...@citrix.com>>: Hi Jan-Arve, In which order have you tried adding vCPUs and NICs? i.e. After creating VM snapshot or before creating snapshot. And have you deleted VM snapshots before adding vCPUs and NICs? Regards, Anshul On 24-Apr-2015, at 5:58 pm, Jan-Arve Nygård <jan.arve.nyg...@gmail.com<mailto:jan.arve.nyg...@gmail.com> <mailto:jan.arve.nyg...@gmail.com>> wrote: Hi, With 4.5 there are some restrictions applied to VMs that have VM snapshots. According to CLOUDSTACK-7688 <https://issues.apache.org/jira/browse/CLOUDSTACK-7688> VM snapshot stops working when the following operations are performed on VM with VM snapshots: 1. Volumes of VM are migrated to other storage 2. Add and remove NIC to/from VM 3. Attach and Detach volume to VM 4. Scale up/down of VM(change service offering) 5. Volume snapshot which is not major use case in this scenario 6. Resize volume 7. Live migration of VM which involves storage migration Does anyone have more technical details about why this is restricted? I tried some quick tests with XenServer 6.5 and CS 4.5.1 and I was able to both revert and take VM snapshots in CloudStack while adding vCPU and NICs on the hypervisor. Thanks, -thinktwo