This is a discussion topic for the following Common Issue:
You can discuss the problem and its solutions here, but please note that debugging and technical feedback should primarily go to the issue trackers (e.g. Bugzilla) linked in the Common Issue, because that’s the place that developers watch, not here.
If there are any updates/changes/amendments for the Common Issue description, which you believe should be performed, please post it here.
Please see the Common Issue for solution/workarounds:
My F41 Silverblue /etc/fstab contains subvol=root,compress=zstd:1,x-systemd.device-timeout=0 and the same parameters for other subvolumes. Should I remove x-systemd.device-timeout=0 from them (or maybe add it to subvol=root’s kargs?) and add ro to subvol=root? If yes, can I do it before rebasing to F42?
Only add the compress=zstd:1 part to the kernel command line. Don’t add x-systemd.device-timeout=0 or ro to the kernel command line.
You can do it anytime. Before rebasing to F42 is fine.
I have the following kernel arguments, which specify zstd compression and noatime:
$ rpm-ostree kargs
rhgb quiet root=UUID=c9abf553-35aa-4590-b0d0-de337c28bddd rw ostree=/ostree/boot.0/fedora/bbfc12aa3893a0b8045484542828d31e113339344b94475623d47b05d418cd27/0 amd_pstate=guided rootflags=subvol=root,compress=zstd,noatime
But I see that the composefs overlay at / has the following options, which has no compression and relatime:
findmnt -T /
TARGET SOURCE FSTYPE OPTIONS
/ composefs overlay ro,relatime,seclabel,lowerdir+=/run/ostree/.private/cfsroot-lower,datadir+=/sysroot/ostree/repo/objects,redirect_dir=on,metacopy=on
What’s the resultant behavior? Is the immutable base commit data compressed, and any overlaid data non-compressed?
Thank you, Timothée, for your help!
You need to look at the /sysroot mount point. The options set on the command line are for the real root mount point, which ends up at /sysroot in the final system. The composefs / is not mounted using any of those options.