HOWTO - GPT/UEFI install with full disk encryption: BTRFSonLUKS with separate root, home and pkg subvolumes; hibernation with a swapfile; auto-snapshots with easy system rollback (GUI); boot into snapshots

BONK · July 25, 2020, 6:05pm

@ricklinux maybe make it a wiki post so they can edit it there?

ricklinux · July 25, 2020, 6:11pm

Not sure how to do that.

ricklinux · July 25, 2020, 6:12pm

When the system boots it still shows no device for hibernation.

BONK · July 25, 2020, 6:23pm

Click the title of the first post, click the three dots at the bottom, click the wrench, and it will open a sub menu with the selection make wiki.

ricklinux · July 25, 2020, 6:25pm

Then it still has to be edited. I thought there already was a wiki for this tutorial? Hmm? I didn’t get any training @Bryanpwo

ricklinux · July 25, 2020, 6:27pm

@2000
I feel dumb now! Am i missing something? Like fstab? It reports no resume device for hibernation or something like that on boot.

[ricklinux@eos-cinnamon ~]$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a device; this may
# be used with UUID= as a more robust way to name devices that works even if
# disks are added and removed. See fstab(5).
#
# <file system>             <mount point>  <type>  <options>  <dump>  <pass>
UUID=6B70-A3D2                            /boot/efi      vfat    umask=0077 0 2
/dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422 /              btrfs   subvol=@,defaults,noatime,space_cache,autodefrag,compress=zstd,compress=zstd 0 0
/dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422 /home          btrfs   subvol=@home,defaults,noatime,space_cache,autodefrag,compress=zstd,compress=zstd 0 0
tmpfs                                     /tmp           tmpfs   defaults,noatime,mode=1777 0 0
/dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422 /var/cache/pacman/pkg btrfs subvol=@var-cache-pacman-pkg,defaults,noatime,space_cache,autodefrag,compress=zstd,compress=zstd 0 0

/dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422 /swap          btrfs   subvol=@swap,defaults,compress=no 0 0
/swap/swapfile none swap defaults 0 0
[ricklinux@eos-cinnamon ~]$

Bryanpwo · July 25, 2020, 6:28pm

We don\t use that part of the forum software. It is a wiki article, but if it needs editing then @2000 is the one to do it.

ricklinux · July 25, 2020, 6:29pm

He said it wouldn’t work so i’m not sure what is the problem.

ricklinux · July 25, 2020, 6:35pm

@2000
It say’s in fstab no swap file? But it shows:

[ricklinux@eos-cinnamon ~]$ swapon --show
NAME           TYPE SIZE USED PRIO
/swap/swapfile file   8G   0B   -2
[ricklinux@eos-cinnamon ~]$

csteinforth · July 25, 2020, 6:37pm

May this be due to fallocate vs. dd?

2000 · July 25, 2020, 6:38pm

Your fstab seems to be correct.
I’m somewhat stumped at this point; only thing I can think of atm is recreating the whole swapfile.

sudo swapoff
sudo rm /swap/swapfile

sudo truncate -s 0 /swap/swapfile
sudo chattr +C /swap/swapfile
sudo btrfs property set /swap/swapfile compression none

sudo fallocate -l 8G /swap/swapfile

sudo chmod 600 /swap/swapfile
sudo mkswap /swap/swapfile
sudo swapon /swap/swapfile

I’ve been reading about some troubles with swapfile creation with fallocate; as an alternative you could try dd instead

dd if=/dev/zero of=/swap/swapfile bs=1 count=0 seek=8G

[Edit: csteinforth had the same idea, ]

You would then have to get the new resume-offset value and adjust /etc/default/grub accordingly; followed by sudo grub-mkconfig -o /boot/grub/grub.cfg

csteinforth · July 25, 2020, 6:41pm

@2000 maybe we had the same thougt.

ricklinux · July 25, 2020, 6:41pm

Strange? First command say’s bad usage? So maybe there is no swap as it shows in fstab even though it shows otherwise with the command. Not even sure i’m doing it right. (Wrong command?)
swapon --show?

2000 · July 25, 2020, 6:42pm

Just ignore the swapoff error.

ricklinux · July 25, 2020, 6:42pm

Each command is just giving errors?

2000 · July 25, 2020, 6:45pm

Is /swap listed if you run … ?
findmnt -nt btrfs

ricklinux · July 25, 2020, 6:46pm

[ricklinux@eos-cinnamon ~]$ ls /swap
swapfile
[ricklinux@eos-cinnamon ~]$ findmnt -nt btrfs
/      /dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422[/@]  btrfs  rw,noat
├─/run/timeshift/backup
│      /dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422      btrfs  rw,rela
├─/home
│      /dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422[/@home]
│                                                                 btrfs  rw,noat
├─/swap
│      /dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422[/@swap]
│                                                                 btrfs  rw,rela
└─/var/cache/pacman/pkg
       /dev/mapper/luks-c2711aa5-335d-45c6-ad4a-613eecc21422[/@var-cache-pacman-pkg]
                                                                  btrfs  rw,noat
[ricklinux@eos-cinnamon ~]$

ricklinux · July 25, 2020, 6:47pm

@2000
Why does it say in the fstab swap file none?
Edit: Maybe the None is just something under a column?

2000 · July 25, 2020, 7:00pm

OK, /swap is an active subvolume, so you should be able to create a swapfile here. One problem less.

This is the mount directory; in the case of swap “none” is correct. See ArchWiki.

You really should be able to create a swapfile with the below commands. (?)

sudo truncate -s 0 /swap/swapfile
sudo chattr +C /swap/swapfile
sudo btrfs property set /swap/swapfile compression none

sudo dd if=/dev/zero of=/swap/swapfile bs=1 count=0 seek=8G

sudo chmod 600 /swap/swapfile
sudo mkswap /swap/swapfile
sudo swapon /swap/swapfile

sudo grub-mkconfig -o /boot/grub/grub.cfg

ricklinux · July 25, 2020, 7:02pm

Something is stopping it?

[ricklinux@eos-cinnamon ~]$ sudo truncate -s 0 /swap/swapfile
[sudo] password for ricklinux: 
truncate: failed to truncate '/swap/swapfile' at 0 bytes: Text file busy
[ricklinux@eos-cinnamon ~]$

I’ll try a restart and see.