Verifying BTRFS Snapshot Was Captured Successfully?

[PhysicistSarah]

So I just did my first BTRFS snapshot of my home and system folders. Everything appears to be fine and the previously clear HDD now shows the proper amount of usage.

I'm not sure about the snapshot of my home folder though. It shows the proper size, but my home folder is encrypted using the typical home folder encryption scheme on 18.04.01. In the folder I see 2 files telling me that I need to decrypt the data, but can I be sure that I can just restore this and it will restore successfully?

[oshunluvr]

Try it. What are you supposing will go wrong if you just try it?

Based on what you describe above, it sounds like you made a backup, not just a snapshot. If you made a backup, all is the same in both subvolumes - the source and the backup. Remember a "snapshot" must exist on the same file system as the source subvolume. If you move or copy it to another file system, it's no longer a snapshot, it's a backup (or copy).

I can't speak about encryption as I don't have a need for it, but I can't imagine why making a snapshot or backup would change anything. Frankly, it sounds like your over-thinking this a bit. BTRFS snapshots aren't very complicated.

[PhysicistSarah]

It's a backup

I don't know, I guess I'm just concerned that it might not work. Don't want to lose my data lol.

I think it's definitely better than Duplicity.

Hmm, I actually just read this line from Grey's tutorial:

Since the "-r" parameter was not use the @ and @home snapshots just created will be read-write. Using a read-only snapshot for @ or @home will prevent those subvolumes from being mounted during boot up.

Does this mean that snapshots of @ and @home need to be read-write to be usable?

[oshunluvr]

Does this mean that snapshots of @ and @home need to be read-write to be usable?

They are usable as read-only in the sense that you can mount, access files, and send|receive them. Read-only status is required to send a snapshot to prevent data corruption. So you could mount a backup subvolume, but not make any changes in it.

Luckily, you can easily change a subvolume from read-only to read-write and vice-versa because it's just a toggle:

sudo btrfs property set -ts @Subvolume_name ro false

does the trick. Obviously "true" would set it to read-only.

[PhysicistSarah]

Wow, I actually didn't know that. I assumed once it was read-only that was it. I'll have to record that one.

[oshunluvr]

Wow, I actually didn't know that. I assumed once it was read-only that was it. I'll have to record that one.

Yes, BTRFS is awesome...

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