Hi, with btrfs, how do I make a snapshot of the root file system? The purpose is to update software and being able to go back to a previous state if necessary.
There doesn't seem to be a command to create snapshots but only subvolumes? How does a subvolume turn into a snapshot? (The root file system is, of course, not on a subvolume.) How do I merge snapshots? IIRC, when you remove a ZFS snapshot, the older state is merged to the state the snapshot is in. Apparently btrfs can only delete snapshots --- and it seems like a bad idea to delete the root file system. How would I boot from it when it's been deleted? Can I make a snapshot on a different volume? The manpage doesn't say that the destination of a subvolume must be on the same volume, and in any case, I should be able to do that.
