On 10/4/24 11:05, Zbigniew Jędrzejewski-Szmek wrote:
Hi folks, I was recently doing a bunch of test reinstalls of Fedora [1], looking to see if it's complicated to retain the user directories during a reinstall. The answer is, sadly, that it's possible only with some manual tinkering. This is a known problem [2]. With a little bit of trickery, Anaconda will let the "home" subvolume be and install the system to a new "root" subvolume, so user data is preserved. But then after a reboot a new user will be created, because the old user is not hooked up into /etc/passwd. We actually have a partial solution for this: systemd-homed. With systemd-homed the information about the user is maintained in the user directory/subvolume/partition, e.g. /home/username.homedir. After a reinstall, ideally nothing needs to be done and the user account is ready to be used. The primary purpose of systemd-homed is to use per-user encryption using loopback devices. This still has various problem related to resizing and suspend. Work is being done [see 3,4 for recent developments], but it's not at a point where we can recommend it. But systemd-homed has a mode where the user "home" is just a normal directory or btrfs subvolume with some metadata stored in files [5]. Some work would be needed [6] to make this work smoothly, but it doesn't seem like too much. (Mostly filing down some rough edges in systemd-homed and adding pam_home_systemd and nss_systemd in various authselect profiles.) Thus the question: would this be something worth looking into? [1] https://discussion.fedoraproject.org/t/feedback-anaconda-web-ui-partitioning/108995/65 [2] https://discussion.fedoraproject.org/t/its-difficult-to-reformat-a-btrfs-partition-subvolume-in-the-installer/89052 [3] https://cfp.all-systems-go.io/all-systems-go-2024/talk/FFY3BB/ [4] https://www.youtube.com/watch?v=3e3IhBBU0JY [5] https://systemd.io/HOME_DIRECTORY/ [6] When I tested this today, this actually doesn't work. systemd-homed does a misguided check that break reinstalls. We'd need to figure out some solution here. Most likely just conditionalize that part of the code. Zbyszek
The common use case for this is the Fedora laptop user which in nearly every case is going to have one local user account.
I have always split /home from the rest of the system and I know others do as well. I would rather see anaconda modified so that if I am creating a user account at install time, check for /home/USERNAME and if USERNAME matches and the UID and GID matches, just don't create the home directory. That is, -M on useradd(8).
-- David Cantrell <dcantrell@xxxxxxxxxx> Red Hat, Inc. | Boston, MA | EST5EDT -- _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx 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/devel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
