qemu-nbd ok, but guestfish/virt-rescue ?

Hi,

is guestfish/virt-rescue usage possible/safe on stopped vm or unused disks on pve itself?

I found some old disks on an old, unused iscsi LUN, which once was an lvm/iscsi storage in pve 1.x and managed to mount it in wheezy vm, then I activated LVs and mounted those volumes in the vm qith qemu-nbd.
Now I know I could use qemu-nbd also with files like .img or .qcow2, or .raw, but I was thinking if tools like guestfish/virt-rescue (or others!) could be used to do some maintenance on pve kvm disks or not...

Marco