In need a non-persitent VM as it is in VCENTER

Community Support Storage
1

Hello,

I’m a teacher, and we have some VMs used by students. The goal is to have clean machines at the beginning of each class. In vCenter, the non-persistent VM option was perfect: each time the VMs were shut down and started up, they were clean.

Is there a similar option in OpenNebula? It seems that the only way is to terminate and redeploy them, which is time-consuming.

Thanks a lot,
Benjamin

2

You can use VM snapshots to capture the clean state and after the class is finished, revert to it. You can automate the revert process as well by tying it to the VM going to POWEROFF after a shutdown action.

3

Thanks a lot, I’ll try that.

4

Hello,

Maybe you can give me a suggestion…

I’ve a ruby script which restore the disk snapshot when the VM is in poweroff.
My concern is that after a snapshot restore, the state is changing back again to power off.
Then, the hook is triggered again, and it’s a never finishing loop…

…
Wed Mar 5 06:51:46 2025 [Z0][LCM][I]: VM disk snapshot operation completed.
Wed Mar 5 06:51:46 2025 [Z0][VM][I]: New state is POWEROFF
Wed Mar 5 06:51:46 2025 [Z0][VM][I]: New LCM state is LCM_INIT
Wed Mar 5 06:51:46 2025 [Z0][VM][I]: New state is ACTIVE
Wed Mar 5 06:51:46 2025 [Z0][VM][I]: New LCM state is DISK_SNAPSHOT_REVERT_POWEROFF
Wed Mar 5 06:51:47 2025 [Z0][LCM][I]: VM disk snapshot operation completed.
Wed Mar 5 06:51:47 2025 [Z0][VM][I]: New state is POWEROFF
Wed Mar 5 06:51:47 2025 [Z0][VM][I]: New LCM state is LCM_INIT
Wed Mar 5 06:51:48 2025 [Z0][VM][I]: New state is ACTIVE
Wed Mar 5 06:51:48 2025 [Z0][VM][I]: New LCM state is DISK_SNAPSHOT_REVERT_POWEROFF
Wed Mar 5 06:51:49 2025 [Z0][LCM][I]: VM disk snapshot operation completed.
Wed Mar 5 06:51:49 2025 [Z0][VM][I]: New state is POWEROFF
Wed Mar 5 06:51:49 2025 [Z0][VM][I]: New LCM state is LCM_INIT
Wed Mar 5 06:51:49 2025 [Z0][VM][I]: New state is ACTIVE
Wed Mar 5 06:51:49 2025 [Z0][VM][I]: New LCM state is DISK_SNAPSHOT_REVERT_POWEROFF
…

oneadmin@debian-opennebula-R2:~/remotes/hooks$ onehook list
ID NAME TYPE
5 restore_snapshot_stud_hook state
oneadmin@debian-opennebula-R2:~/remotes/hooks$ onehook show 5
HOOK 5 INFORMATION
ID : 5
NAME : restore_snapshot_stud_hook
TYPE : state
LOCK : None

HOOK TEMPLATE
ARGUMENTS=“$TEMPLATE”
COMMAND=“restore_stud_snapshot_hook.rb”
LCM_STATE=“LCM_INIT”
REMOTE=“NO”
RESOURCE=“VM”
STATE=“POWEROFF”

Do you have an advice ?

Thanks a lot,
Benjamin