As I understand it, once a HassOS image (either for an RPi or for a VM) is initialized, it cannot expand the size of the partition it uses. This is a problem if one needs to add storage - easy enough to move the image to a larger SD card or allocate more space to the VM, but neither does anything if HassOS doesn’t expand its internal partitions.
I know for VMs there’s a workaround, where you take a snapshot, create a new VM, expand it before starting for the first time, then restore. However, a) this is a bit of a kludge, and b) I’ve never managed to actually get it to work…
After VM shutdown I just removed all snapshots of the HASSOS VM and increased the size of the vdisk.
When powering the VM back on it actually took all the steps to make use of the additionaly storage space on its own. Nothing in particular that I needed to do than what I wrote above.
to resize the vdisk there must not be any snapshots of the vm.
you may remove snapshots at Virtual Machines > HASS-VM-NAME > Actions > Snapshots > Manage Snapshots