This is just what the Calamares installer created. I’m not very knowledgeable about btrfs. I myself use the set up on the wiki by @2000
It is indeed true, that grub has its problems with btrfs.
I do have /boot on btrfs, so its included in a snapshot of /. No problem if i revert to that snapshot
(think of a kernel update when doing a system upgrade, if you revert to a previous snapshot, /boot remains untouched if not included in the snapshot - because its on ext4 for example - so it gets more difficult in that case, but not impossible to solve. For example: https://wiki.archlinux.org/title/Snapper#Backup_non-Btrfs_boot_partition_on_pacman_transactions)
But, i therefore need as well:
GRUB_DEFAULT=0 (-> boot the first entry by default, i read about other values not having effect, too) GRUB_SAVEDEFAULT=false ( or just comment that line)
no “sparse file” error on boot after those 2 changes in /etc/default/grub (& grub-mkconfig -o … of course)
There is a nice reply in the fedora forum about the
grubenv problem (-> sparse file error on boot), when on btrfs.
Read the answer from Chris Murphy:
“…Because of this, writes to grubenv are disallowed by GRUB when it detects the grubenv file is on Btrfs…”
Now we come a little closer to the matter …
The tutorial of @2000 I must first take my time to look at. Is already something violent for me old fart …
I see, maybe something to consider? https://wiki.archlinux.org/title/Btrfs#Compression
@2000 was there an reason to not include compression?
I myself am using it but never made any specific tests so I can’t say what the effects are performance wise, but it seems to do a good job on storage:
------------------------------------------------------------------------------ 20:00:14 - Compression statistics: Processed 4601138 files, 11760736 regular extents (44625115 refs), 2409648 inline. Type Perc Disk Usage Uncompressed Referenced TOTAL 89% 1.1T 1.3T 5.2T none 100% 1.1T 1.1T 4.5T lzo 20% 25M 120M 724M zstd 34% 74G 213G 723G
I think you misunderstood my answer. What i posted was from a Calamares install changing the default file system to btrfs instead of ext4 just to show @anon92247698 the result and checking if i got the same error.
Personally myself i use the btrfs setup from the wiki by @2000. Not sure about all the details of it. I just installed it and it works.
This is my btrfs installation using the quick copy & paste version on the wiki with encryption.
[ricklinux@eos-xfce ~]$ 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=4439-BD01 /boot/efi vfat umask=0077 0 2 /dev/mapper/luks-a209e59c-bdbd-43ec-a367-17786b03066c / btrfs subvol=@,defaults,noatime,space_cache,autodefrag,compress=zstd,compress=zstd 0 0 /dev/mapper/luks-a209e59c-bdbd-43ec-a367-17786b03066c /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-a209e59c-bdbd-43ec-a367-17786b03066c /var/cache/pacman/pkg btrfs subvol=@var-cache-pacman-pkg,defaults,noatime,space_cache,autodefrag,compress=zstd,compress=zstd 0 0 /dev/mapper/luks-a209e59c-bdbd-43ec-a367-17786b03066c /swap btrfs subvol=@swap,defaults,compress=no 0 0 /swap/swapfile none swap defaults 0 0 [ricklinux@eos-xfce ~]$
Edit: I don’t see any separate /boot partition unless it’s hidden.