Possible advantage of setting @/home subvolume as Btrfs?

English Install/Boot/Login
#1

I’m playing with Tumbleweed in a VM. I want to see if there’s any advantage to set my @/home as Btrfs so I can take snapshots of it (in addition to taking snapshots of @/root).

  • Say during install I set my @/home to be Btrfs.
  • Say I got a lot of personal files in my @/home like lots of movies, say about 1TB.
  • Say I’m taking daily Btrfs snapshots of @/home and storing them on an external drive.
  • Then say I accidentally DBAN all the files in my @/home subvolume so they’re all gone.

Then I can quickly restore all the files cuz I got a recent snapshot. So here’s my question: Is that a possible advantage of setting @/home to be Btrfs?

If I only have an Rsync external backup of the files, that can take many hours to restore from an external USB-3 connected spinning HDD. And the Btrfs snapshot can be restored in a few seconds.

In this example, @/root and @/home both reside on the same internal nvme in my laptop.

#2

What are the @ doing here? They may at the most create confusion.

And I assume you mean / and not /root!

And what is a “subvolume”?

#3

If “/home” is a separate partition and separate file system, then it really isn’t a “subvolume”.

Okay, your not really familiar with the terminology. But you will confuse some people.

I don’t really have an opinion on using “btrfs” for a separate “/home” file system. Yes, using “btrfs” might allow rollbacks. But I would think it more important to make periodic backups. If the disk drive fails, a rollback won’t help.

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#4

I see @/root and @/home in this image from Tumbleweed install:

2023 06 16 Tumbleweed partitions subvolumes
2023 06 16 Tumbleweed partitions subvolumes1047×798 83.3 KB

I think @/home is XFS by default. In my original post, I set @/home to Btrfs to properly setup my question. For the purposes of my question, assume that @/home is manually converted from XFS to Btrfs during install.

Does this resolve the confusion?

The essence of my question is: Is a Btrfs snapshot restore of 1TB of files a lot faster than an Rsync restore of the same 1TB of files from an external USB-3 spinning HDD?

Is “@” the real “root”? Then what is “@/root”? Are they different? Are there 2 different root subvolumes? Maybe that’s the confusion? I’m just going by what I see in the image.

What’s the difference between “@” and “@/root”?

#5

Those with @ are Brtfs subvolumes. They are part of your Btrfs file system for /.

They are NOT separate file systems. Thus you have NOT a separate file system for /home (and it certainly is not XFS).

All the above and also all in the other thread are based on one big misunderstanding.

I am sorry to say so.

Please look at (and you may show it also here):

lsblk -f
#6

I ran the command. Very nice, that clears up the confusion. Thanks.

But I still have the same question; Is a Btrfs restore of lots of files a lot quicker than restoring the same files with Rsync?

#7

snapper is not a backup. it is a history of changes to system files. It is useful to roll back to a pervious system state it is not a backup of user data. BTRFS with sub volumes is essentially multiple Btrees mixed together They are not separated like a partition.

If you do setup a home partition using BTRFS you would need to do a special setup of snapper the default setup would not be usable since excludes /home from snapshots

#8

OK, thanks. How do I mark a topic as Solved?

#9

When you say so, as you did, that is OK.