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Read-only and read-write snapshots are possible with LVM, ZFS, Btrfs, and many commercial storage solutions. One reason why you would want a writable snapshot
by antongribok 9y ago
Read-only and read-write snapshots are possible with LVM, ZFS, Btrfs, and many commercial storage solutions.
One reason why you would want a writable snapshot is during backup validation. An application may need to do crash recovery before being able to read data, and having a writable filesystem makes things a lot easier.
I know that ZFS and LVM both send writes to a separate area, so the original snapshot is never modified (don't know about Btrfs implementation details).
- takeda 9y agoYes, what I said in ZFS you can instantly (and without using extra space) create a writable filesystem from snapshot using zfs clone (you can create multiple filesystems from one snapshot), but snapshots by itself are always read only.