F42 Silverblue and fstrim

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1

The weekly fstrim service does not seem to trim the root filesystem in F42 Silverblue. This is probably a result of using composefs and /sysroot being mounted read-only.
Can anyone explain how this is going to work going forward?

2

Did trim work F41 Silverblue?

I’m curious; how does SSD trim work on atomic/immutable with read-only filesystems?

3

Yes, it did work on F41 Silverblue.
In F41 the root filesystem was still available as read-write mounted at /. Only the /sysroot mount was read-only.
How it is supposed to work now in F42, I don’t know.

I should mention that my root filesystem is XFS and not BTRFS if that makes a difference.

1 Like
4

Am I really the only one having this problem on F42 Silverblue?

Service “fstrim.service” (triggered weekly by “fstrim.timer”) silently ignores the root filesystem because it is read-only.

Here is the output from the journal:

Apr 21 07:40:10 skylark systemd[1]: Starting fstrim.service - Discard unused blocks on filesystems from /etc/fstab...
Apr 21 07:45:22 skylark fstrim[5452]: /srv/virt: 128 GiB (137438953472 bytes) trimmed on /dev/sda5
Apr 21 07:45:22 skylark fstrim[5452]: /home: 48 GiB (51539607552 bytes) trimmed on /dev/sda4
Apr 21 07:45:22 skylark fstrim[5452]: /boot/efi: 498,4 MiB (522616832 bytes) trimmed on /dev/sda1
Apr 21 07:45:22 skylark fstrim[5452]: /boot: 1,6 GiB (1699303424 bytes) trimmed on /dev/sda2
Apr 21 07:45:22 skylark systemd[1]: fstrim.service: Deactivated successfully.
Apr 21 07:45:22 skylark systemd[1]: Finished fstrim.service - Discard unused blocks on filesystems from /etc/fstab.

The root partiton is “/dev/sda3” as seen here:

[xyz@skylark:~]$ df -hT
Filesystem     Type      Size  Used Avail Use% Mounted on
/dev/sda3      xfs        48G   12G   37G  24% /sysroot
composefs      overlay    21M   21M     0 100% /
devtmpfs       devtmpfs  4,0M     0  4,0M   0% /dev
tmpfs          tmpfs     3,8G   96K  3,8G   1% /dev/shm
efivarfs       efivarfs   64K   22K   37K  38% /sys/firmware/efi/efivars
tmpfs          tmpfs     1,6G  1,9M  1,6G   1% /run
tmpfs          tmpfs     1,0M     0  1,0M   0% /run/credentials/systemd-journald.service
tmpfs          tmpfs     3,8G   16K  3,8G   1% /tmp
/dev/sda4      xfs        48G   18G   31G  37% /var/home
/dev/sda5      xfs       128G   91G   38G  71% /var/srv/virt
/dev/sda2      ext4      2,0G  326M  1,5G  18% /boot
/dev/sda1      vfat      511M   13M  499M   3% /boot/efi
tmpfs          tmpfs     1,0M     0  1,0M   0% /run/credentials/systemd-resolved.service
tmpfs          tmpfs     776M  188K  775M   1% /run/user/1000
[xyz@skylark:~]$