News for hackers. Stuff that matters.

A comment on Initial Hammer2 filesystem implementation. Parent comment

Re:Initial Hammer2 filesystem implementation by antongribok on Tuesday August 22, 2017 @01:02AM (#15069847)
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).

[ Parent | on HN ]
Re:Initial Hammer2 filesystem implementation by takeda on Tuesday August 22, 2017 @05:07PM (#15076402)
Yes, 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.
[ Parent | on HN ]