Arch Linux

PhilArch33

Member

Registered: 2026-07-24

Posts: 5

Snapper snapshots ok in @ / subvolume or not?

Hello, I'm a newbie in this forum as well as with Arch. (Love it btw!) So go ahead and start barking at me your complaints about how I'm in the wrong forum or not given proper logs, etc. I can take it! I'm a big man! lol

I just have what should be a simple question. I'm getting conflicting information from Gemini.

I used this btrfs subvolumes layout during archinstall:
        @       /
        @home   /home
        @log    /var/log
        @pkg    /var/cache/pacman/pkg

- I DID NOT create a ./snapshots subvolume. The snapshots reside in the @(/) subvolume. Is that ok? According go Gemini, it's unclear. I might lose all my snapshots in case of a full root rollback?
- Would it be better if I created a @snappers /.snapshots subvolume? or make things worse? Because as you see in the below logs output of <brtfs subvolume list />, Snapper looks like it creates a subvolume for each snapshot anyway. So am I ok as is?

A little log to show I'm really using Arch!

lsblk -f
NAME   FSTYPE  FSVER            LABEL       UUID                                 FSAVAIL FSUSE% MOUNTPOINTS
sda                                                                                             
├─sda1 vfat    FAT32                        2FE0-18DF                             856.6M    16% /boot
├─sda2 swap    1                            40b40cf7-15fd-4a1c-8599-e209e4277dad                [SWAP]
└─sda3 btrfs                                1fdeb98b-3782-4a64-a89e-de6d3e01daef  229.1G    50% /home
                                                                                                /var/log
                                                                                                /var/cache/pacman/pkg
                                                                                                /
sdb                                                                                             
├─sdb1                                                                                         
├─sdb2 swap    1                swap        9d3f4f14-a84e-4ef6-8fe6-b561d0cb2f26               
└─sdb3 ext4    1.0              root        2c56b5e8-2c33-4bf5-b9d0-a78444f97fca               
sdc                                                                                             
└─sdc1 ext4    1.0                          79218a50-6059-42c9-b7c4-2511b4e500a1  833.5G    49% /MainBackup
sdd    iso9660 Joliet Extension ARCH_202607 2026-07-01-16-36-20-00                             
├─sdd1 iso9660 Joliet Extension ARCH_202607 2026-07-01-16-36-20-00                             
└─sdd2 vfat    FAT32            ARCHISO_EFI 6A45-4204                                           

sudo btrfs subvolume list /
[sudo] password for philip:
ID 256 gen 3125 top level 5 path @
ID 257 gen 3125 top level 5 path @home
ID 258 gen 3119 top level 5 path @log
ID 259 gen 2955 top level 5 path @pkg
ID 260 gen 13 top level 256 path var/lib/portables
ID 261 gen 13 top level 256 path var/lib/machines
ID 262 gen 2957 top level 256 path .snapshots
ID 263 gen 2959 top level 257 path @home/.snapshots
ID 264 gen 72 top level 263 path @home/.snapshots/1/snapshot
ID 265 gen 74 top level 262 path .snapshots/1/snapshot
ID 266 gen 117 top level 262 path .snapshots/2/snapshot
ID 267 gen 148 top level 262 path .snapshots/3/snapshot
ID 268 gen 150 top level 262 path .snapshots/4/snapshot
ID 269 gen 171 top level 262 path .snapshots/5/snapshot
ID 270 gen 172 top level 262 path .snapshots/6/snapshot
ID 271 gen 200 top level 263 path @home/.snapshots/2/snapshot
ID 272 gen 201 top level 262 path .snapshots/7/snapshot
ID 273 gen 301 top level 262 path .snapshots/8/snapshot
ID 274 gen 303 top level 262 path .snapshots/9/snapshot
ID 275 gen 342 top level 262 path .snapshots/10/snapshot
ID 276 gen 343 top level 262 path .snapshots/11/snapshot
ID 277 gen 363 top level 263 path @home/.snapshots/3/snapshot
ID 278 gen 364 top level 262 path .snapshots/12/snapshot
ID 279 gen 438 top level 262 path .snapshots/13/snapshot
ID 280 gen 439 top level 262 path .snapshots/14/snapshot
ID 281 gen 444 top level 262 path .snapshots/15/snapshot
ID 282 gen 445 top level 262 path .snapshots/16/snapshot
ID 283 gen 453 top level 262 path .snapshots/17/snapshot
ID 284 gen 454 top level 262 path .snapshots/18/snapshot
ID 285 gen 485 top level 263 path @home/.snapshots/4/snapshot
ID 286 gen 486 top level 262 path .snapshots/19/snapshot
ID 287 gen 580 top level 263 path @home/.snapshots/5/snapshot
ID 288 gen 581 top level 262 path .snapshots/20/snapshot
ID 289 gen 679 top level 263 path @home/.snapshots/6/snapshot
ID 290 gen 680 top level 262 path .snapshots/21/snapshot
ID 291 gen 772 top level 263 path @home/.snapshots/7/snapshot
ID 292 gen 773 top level 262 path .snapshots/22/snapshot
ID 293 gen 878 top level 263 path @home/.snapshots/8/snapshot
ID 294 gen 879 top level 262 path .snapshots/23/snapshot
ID 295 gen 975 top level 263 path @home/.snapshots/9/snapshot
ID 296 gen 975 top level 262 path .snapshots/24/snapshot
ID 297 gen 1043 top level 262 path .snapshots/25/snapshot
ID 298 gen 1045 top level 262 path .snapshots/26/snapshot
ID 299 gen 1251 top level 262 path .snapshots/27/snapshot
ID 300 gen 1252 top level 262 path .snapshots/28/snapshot
ID 301 gen 1524 top level 262 path .snapshots/29/snapshot
ID 302 gen 1525 top level 262 path .snapshots/30/snapshot
ID 303 gen 2433 top level 262 path .snapshots/31/snapshot
ID 304 gen 2437 top level 262 path .snapshots/32/snapshot
ID 305 gen 2953 top level 262 path .snapshots/33/snapshot
ID 306 gen 2954 top level 262 path .snapshots/34/snapshot

OS-AC713

Member

Registered: 2026-07-30

Posts: 3

Re: Snapper snapshots ok in @ / subvolume or not?

Hello!

I understand your concern, but I'm ready to help.

1. In Btrfs, subvolumes are independent entities; even if your .snapshots is located within the root @ (tree-wise), it is a separate subvolume.
2. Standard rollback doesn't touch anything not specified in the command. The system simply changes the pointer to the old version of @ and leaves the rest alone.

3. Your log also indicates that .snapshots is a separate subvolume with ID 262. Btrfs will rollback your @ (ID 256) and simply ignore the other ID since it wasn't specified in your command.

4. Snapper rollback works like this:
It swaps: Snapshot number 10 becomes the new root, and the old root becomes the new snapshot. The snapshot chain remains intact.
5. You don't have to create a subvolume; the archinstall utility has created one for you with ID 262.

PhilArch33

Member

Registered: 2026-07-24

Posts: 5

Re: Snapper snapshots ok in @ / subvolume or not?

Thank you for your reply. I understand better now. Not looking forward to experience a rollback but I think I'll understand a lot more when it happens. Have you had the opportunity to rollback yourself? Is it really as easy as picking a snapshot from GRUB and boot with it?

OS-AC713

Member

Registered: 2026-07-30

Posts: 3

Re: Snapper snapshots ok in @ / subvolume or not?

I haven't had to rollback yet, so I can't speak from personal experience. But I've read enough about it to know that it's essentially just picking a snapshot from GRUB and booting into it. The system handles the rest. I'm confident it'll work when the time comes.

Last edited by OS-AC713 (2026-08-04 22:27:38)

PhilArch33

Member

Registered: 2026-07-24

Posts: 5

Re: Snapper snapshots ok in @ / subvolume or not?

I did some research and apparently booting from a snapshot only boots in read only mode but it allows you to find the right snapshot before the system broke. There's a "rollback" command on the openSUSE systems but apparently in Arch you have to do it manually. Mount your desired snapshot temporarily and overwrite the root subvolume but like you, I'm going to wait until it happens to play around with this.