[Accepted] Make it more clear that "Delete Virtual Machine Data?" will delete all attached disk zvols when deleting a VM

Feature Requests
,
1

I’m running 25.04.2.

Problem/Justification
I had created a temporary Ubuntu VM to pull some files off of an another zvol. After creating the VM, I attached the zvol as a disk device. When I was done I deleted the VM and checked the “Delete Virtual Machine Data?” box (but not “Force Delete?”). I was surprised to find that both the OS zvol and my manually attached zvol were deleted. My expectation was that only the OS zvol that was created when I created the VM would be deleted.

Potential Solutions
I don’t have strong opinion on exactly what should or shouldn’t be deleted when the box is checked, but assuming the current behavior I do think that there are some low-effort changes that could make the behavior significantly more clear.

The simplest option would be to improve the tooltip. It currently reads:

Set to remove the data associated with this Virtual Machine (which will result in data loss if the data is not backed up). Unset to leave the data intact.

IMO, this is way too abstract and ambiguous given the data loss that could occur from misunderstanding. A tooltip that more explicitly detailed what would occur in TrueNAS/zfs terms (e.g. “WARNING: All Disk Device zvols attached to this VM will be destroyed!”) would make accidental deletion less likely.

A further, higher-effort improvement would be to actually list the zvols and anything else that would be deleted when the box is checked.

2 Likes
2

yes, yes, yes. I’ve done this once, and will likely forget and do it again every few years because it is very easy to do and unexpected. A list should be displayed or the behaviour changed.

3

Thanks for the submission, item has beeen accepted. Once we have a confirmed release target I’ll update the thread.

1 Like