I installed a fresh CentOS 7.2 guest (babybrighton) on my host (brighton), and then did this from brighton (where /dev/sdb is a physical device connected to brighton): virsh attach-disk --persistent babybrighton /dev/sdb vdb This worked fine and the disk shows up fine: [root@babybrighton ~]# ls -l /dev/vdb* brw-rw----. 1 root disk 252, 16 Dec  4 20:37 /dev/vdb brw-rw----. 1 root disk 252, 17 Dec  4 20:37 /dev/vdb1 brw-rw----. 1 root disk 252, 18 Dec  4 20:37 /dev/vdb2 brw-rw----. 1 root disk 252, 19 Dec  4 20:37 /dev/vdb3 I now want virsh snapshot-create-as to save babybrighton's state and the data on /dev/vda*, the psuedo-disk I made when creating babybrighton. However, I do not want virsh snapshot-create-as to save the state of /dev/vdb* on babybrighton, because /dev/sdb is an 8TB drive on brighton that holds the babybrighton VM itself. I do want the snapshot to remember that it's mapping /dev/vdb to the host's /dev/sdb, but that's the only information about /dev/vdb that the snapshot should have. I've tried things like: virsh snapshot-create-as --diskspec=vda,snapshot=internal --diskspec=vdb,snapshot=no babybrighton test1 semi external disk  # result error: unsupported configuration: disk 'vdb' must use snapshot mode 'internal' and many similar, but haven't found anything that works, or even if this is possible.I need /dev/vdb available when babybrighton boots, so I can't just run a command after I log into babybrighton.Is there any easy way to accomplish this? If not, what's a good way to keep /dev/vda* synced so I can rollback when needed? Does VirtualBox handle this better? 
How to tell virsh: save state of VM and vdisk, but not attached disk?
virtualbox;virtual machine;kvm