On Sun, Oct 26, 2025, at 3:15 PM, Samuel Sieb wrote:
> compression is set per subvolume. I don't know why Chris said that. > The btrfs docs say it's per mount. Yes, per mount. For the entire file system. $ sudo -i # pwd /root # btrfs sub create /root/root/test # btrfs sub list / | grep test ID 721 gen 1311192 top level 710 path root/test # mount -o subvolid=721,compress=zstd:3 /mnt # mount | grep test /dev/mapper/luks-10d575f0-f041-48a2-b1ed-b1236e03d5e3 on /mnt type btrfs (rw,relatime,seclabel,compress=zstd:1,ssd,space_cache=v2,subvolid=721,subvol=/root43/root/test) Doesn't make it zstd:3 - and in fact if I umount it and mount again without compression, it's still listed as zstd:1 - the mount option is ignored. Whereas: # mount -o remount,compress-force=zstd:3 / # dmesg | tail [24001.045184] BTRFS info (device dm-0 state M): force zstd compression, level 3 # mount | grep btrfs All my btrfs mount points for this file system are now compress-force=zstd:3 not just `/` mount point. Same for autodefrag, notreelog, commitonflush, commit=Nsecs, discards, etc. Funny enough, remount can't substitute another subvolume. -- Chris Murphy -- _______________________________________________ users mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected] Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
