15
timeshift with btrfs: am I doing it right?
(lemmy.kde.social)
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 20 Jul 2023
15 points (94.1% liked)
Linux
48033 readers
948 users here now
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Rules
- Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
- No misinformation
- No NSFW content
- No hate speech, bigotry, etc
Related Communities
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
founded 5 years ago
MODERATORS
Creating a snapshot is not the backup itself. It is basically freezing the current state of your files from this point on and then remembering what has chanced compared to the snapshot. So yes, it is normal that this takes no time since nothing is copied on your hard drive. If you want to backup the snapshot you need to make an actual backup of it. This is possible with btrfs. But since I haven’t done it yet, I can’t tell you the exact command.
https://github.com/digint/btrbk
Is the best tool for automating btrfs snapshots and backups.
How does it compare to snapper? It seems like they do basically the same thing
so it is a completely different process than with rsync... I always thought of the two ways are pretty similar
Copy on write is the difference. As I understand it, a btrfs snapshot takes no space when it's created (beyond the file system record). The filesystem is always writing changes to file chunks as a new copy of the chunk, which is then recorded as a replacement of the old chunk (which is still present on-disk). So a snapshot tracks all of these later changes, and the file system keeps the old file chunks preserved as long as you keep the snapshot. That's why you can mount a btrfs snapshot. It just shows you the volume through the lens of all of these saved changes.
When you delete a snapshot you are then marking these preserved chunks as free space. So that is also quick.
Whoever invented this is a genius, a genius...
thanks for the help!