[How-To] Fix full OS filesystem - GUI login loop

  • Symptoms

    When you try to login to the GUI of OMV you are not being logged in, but the login page shows up again

    Check, if a full root filesystem is the problem

    ssh into your server (check the new user guide on how to ssh into your server) and run following command

    df df will show you the usage of each filesystem

    the output of df will look like this:

    The filesystem dev/sda1 which is mounted on "/" is the OS filesystem. The use of that filesystem is 100% --> the OS filesystem is full.

    Find which folder is filling the filesystem

    in the CLI run

    cd / to change to the root of the OS file system

    du -xhd1 du will show you the size of each folder on the root (x: do not descend into other filesystem; h: display output in human readable format; d1: show only first level of directories)

    the output will look like this:

    (To get only the 10 largest folders/files in order, use du -ahxd1 | sort -hr | head -n 10)

    Identify the largest folder and change into that folder with

    cd foldername replace foldername by the name of the largest folder

    Repeat these steps until you identified the "deepest" folder which is filling your root filesystem.

    Change into that folder and check with ls -al what is inside. ls lists the directory content (a: shows you also hidden entries, l: shows in a long list format)

    Further steps depend on the reason:

    Common Reasons for full OS filesystem

    • Docker (e.g. large media library of plex)
    • a rsync job was running, when the target filesystem was not mounted --> the files were copied to a folder, which was created instead of mount point (usually in /srv/)
      • a symptom of this is, that the results for du and df do not match
        (i.e disk capacity minus reported usage with du is not similar to the result of df)
      • Unmount all drives in /srv from CLI and force the unmount if needed
      • look in each mountpoint directory in /srv and see if anything is in there
      • delete the wrongly created folder (:!:if you are in doubt physically disconnect the related hard drive to not delete the content on that drive:!:)
    • log files are spammed --> check the content of the log file and fix the root cause why the log file is spammed; after you fixed the problem you can reduce the size of the log file to 0 with truncate -s 0 logfile.log replace logfile.log
  • A nice tool to support the process of identifying the folder that is filling the OS filesystem is ncdu

    Install with apt-get install ncdu

    Again move to the root with cd /

    Start ncdu with ncdu -x. Again the option x is preventing ncdu from descending into other filesystems (i.e. your data drives) which might take a long time.

    Sample output:

    ncdu 1.13 ~ Use the arrow keys to navigate, press ? for help
    --- / ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
    2.2 GiB [##########] /usr
    2.2 GiB [######### ] /var
    1.3 GiB [##### ] /boot
    9.7 MiB [ ] /etc
    5.7 MiB [ ] /root
    3.9 MiB [ ] /tmp_urbackup
    1.2 MiB [ ] /srv
    20.0 KiB [ ] /home

    Press q to quite.

  • macom

    Added the Label core
  • If the login loop is not caused by a full file system, try

    • force reload of the GUI (check how this is done for your browser, for FIrefox: Ctrl+Shift+R)
    • clear browser cache
    • open your browser in Privacy/Incognito mode

    and see if the problem persists.

Participate now!

Don’t have an account yet? Register yourself now and be a part of our community!