this post was submitted on 13 Dec 2023
995 points (99.0% liked)

linuxmemes

21311 readers
885 users here now

Hint: :q!

Sister communities:

Community rules (click to expand)

1. Follow the site-wide rules

2. Be civil
  • Understand the difference between a joke and an insult.
  • Do not harrass or attack members of the community for any reason.
  • Leave remarks of "peasantry" to the PCMR community. If you dislike an OS/service/application, attack the thing you dislike, not the individuals who use it. Some people may not have a choice.
  • Bigotry will not be tolerated.
  • These rules are somewhat loosened when the subject is a public figure. Still, do not attack their person or incite harrassment.
    • 3. Post Linux-related content
  • Including Unix and BSD.
  • Non-Linux content is acceptable as long as it makes a reference to Linux. For example, the poorly made mockery of sudo in Windows.
  • No porn. Even if you watch it on a Linux machine.
    • 4. No recent reposts
  • Everybody uses Arch btw, can't quit Vim, and wants to interject for a moment. You can stop now.
    •  

    Please report posts and comments that break these rules!

    Important: never execute code or follow advice that you don't understand or can't verify, especially here. The word of the day is credibility. This is a meme community -- even the most helpful comments might just be shitposts that can damage your system. Be aware, be smart, don't fork-bomb your computer.

    founded 1 year ago
    MODERATORS
    poopsmith@lemmy.world
    zephyr@lemmy.world
    rtxn@lemmy.world
    995
    Can I get a filesystem cleanup on aisle 6? (lemmy.today)
    submitted 11 months ago by CmdrKeen@lemmy.today to c/linuxmemes@lemmy.world
    93 comments fedilink hide all child comments
     
    you are viewing a single comment's thread
    view the rest of the comments
    [–] CameronDev@programming.dev 112 points 11 months ago* (last edited 11 months ago) (3 children)

    It is actually a boot failure. Normally the kernel reads some config from the initrd (the bootloader loads initrd and passes it to the kernel - thanks dan) and then does a bunch of setup stuff, and then it mounts the actual root filesystem, and then switches to using that. In this case, the root filesystem has failed to mount.

    Hardware failure is most likely the cause, but misconfiguration can also make this happen. Probably hardware though.

    If its misconfiguration, an admin can reattempt to mount the root drive on /new_root, and then ctrl-d to get the init system to try again

    ELI5: couldnt open C:/ drive

    Edit: clarified what loads the initrd - as per dans comment.

    [–] dan@upvote.au 7 points 11 months ago* (last edited 11 months ago) (1 children)

    Normally the kernel loads an initrd filesystem,

    The bootloader (GRUB) loads the initrd, not the kernel. The kernel accesses stuff from the initrd, but it's already loaded by that point.

    [–] CameronDev@programming.dev 3 points 11 months ago

    You are correct. Ill add an edit. Thanks!

    [–] RustyNova@lemmy.world 4 points 11 months ago

    Thanks for that!

    Switching to Linux and actually being able to see real time logs made me actually curious how it works, so that's one gear out of the machine demistified

    [–] Synthead@lemmy.world 1 points 11 months ago (1 children)

    The root filesystem mounted fine. That's why the init is starting with all the services on the root disk.

    [–] neidu@feddit.nl 6 points 11 months ago (1 children)

    Not necessarily. I've seen failures like this if the boot partition works, but fails to mount the root partition. systemd then fails to proceed, and shuts down the running services.

    [–] Synthead@lemmy.world 2 points 11 months ago* (last edited 11 months ago) (2 children)

    systemd daemons are configured via /etc/systemd, and systemd itself lives in /usr/lib/systemd/systemd. How can systemd run or start the configured services without the root disk mounted? The initrd (from the boot partition) only contains enough of an environment to call the entrypoint for the init system, not contain the entirety of systemd (or the configured services).

    [–] damium@programming.dev 6 points 11 months ago

    Initrd contains the systemd binary and enough libraries, services, and kernel modules to get booted this far. The system failed at switch root which is where the real root disk is mounted. Initrd can contain as much or as little as needed to get a working system which can be a lot of you are using a network filesystem as a root for instance.

    [–] CameronDev@programming.dev 4 points 11 months ago (1 children)

    Those are all hardware management services (as far as I can tell), and are configured before the root is mounted.

    I have hit this exact error before, that is what failing to mount the root disk looks like. A bunch of services will start, and then you get dropped into a shell (with a login).

    If you want to see it for yourself, change /etc/fstab such that /root is now pointing to the wrong device, and then rebuild your initrd. When you reboot you'll see exactly that output. To fix it, login to the shell and mount your root on /new_root, and ctrl-d to continue the boot (from memory it has a message telling you to do that anyway). When your system boots you can fix fstab and rebuild initrd. Its reversable, but maybe test on a machine you dont care about to be safe :)

    [–] Synthead@lemmy.world 2 points 11 months ago

    Oh interesting! I suppose I have just been very careful with /etc/fstab and I haven't seen systemd fail this way. TIL! Thanks for letting me know!