• Morethanevil
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    1522 months ago

    Cleanup

    Check current disk usage:

    sudo journalctl --disk-usage

    Use rotate function:

    sudo journalctl --rotate

    Or

    Remove all logs and keep the last 2 days:

    sudo journalctl --vacuum-time=2days

    Or

    Remove all logs and only keep the last 100MB:

    sudo journalctl --vacuum-size=100M

    How to read logs:

    Follow specific log for a service:

    sudo journalctl -fu SERVICE

    Show extended log info and print the last lines of a service:

    sudo journalctl -xeu SERVICE

    • macniel
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      382 months ago

      I mean yeah -fu stands for “follow unit” but its also a nice coincidence when it comes to debugging that particular service.

    • slazer2au
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      192 months ago

      sudo journalctl --disk-usage

      panda@Panda:~$ sudo journalctl --disk-usage  
      No journal files were found.  
      Archived and active journals take up 0B in the file system.
      

      hmmmmmm…

    • @[email protected]
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      2 months ago
      user@u9310x-Slack:~$ sudo journalctl --disk-usage  
      Password:  
      sudo: journalctl: command not found  
      
    • @[email protected]
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      82 months ago

      Thank you for this, wise sage.

      Your wisdom will be passed down the family line for generations about managing machine logs.

      • Morethanevil
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        52 months ago

        Glad to help your family, share this wisdom with friends too ☝🏻😃

      • @VirtualOdour
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        22 months ago

        Yeah, if I had dependents they’d gather round the campfire chanting these mystical runes in the husk of our fallen society

    • @[email protected]
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      32 months ago

      Actually something I never dug into. But does logrotate no longer work? I have a bunch of disk space these days so I would not notice large log files

      • Morethanevil
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        2 months ago

        If logrotate doesn’t work, than use this as a cronjob via sudo crontab -e Put this line at the end of the file:

        0 0 * * * journalctl --vacuum-size=1G >/dev/null 2>&1

        Everyday the logs will be trimmed to 1GB. Usually the logs are trimmed automatically at 4GB, but sometimes this does not work

      • @faerbit
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        52 months ago

        It is. The defaults are a little bit more lenient, but it shouldn’t gobble up 80 GB of storage.

  • @[email protected]
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    312 months ago

    Try 60GB of system logs after 15 minutes of use. My old laptop’s wifi card worked just fine, but spammed the error log with some corrected error. Adding pci=noaer to grub config fixed it.

  • @[email protected]
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    2 months ago

    Once I had a mission critical service crash because the disk got full, turns out there was a typo on the logrotate config and as a result the logs were not being cleaned up at all.

    edit: I should add that I used the commands shared in this post to free up space and bring the service back up

  • @wildbus8979
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    Fucking blows my mind that journald broke what is essentially the default behavior of every distro’s use of logrotate and no one bats an eye.

    • @[email protected]
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      2 months ago

      I’m not sure if you’re joking or not, but the behavior of journald is fairly dynamic and can be configured to an obnoxious degree, including compression and sealing.

      By default, the size limit is 4GB:

      SystemMaxUse= and RuntimeMaxUse= control how much disk space the journal may use up at most. SystemKeepFree= and RuntimeKeepFree= control how much disk space systemd-journald shall leave free for other uses. systemd-journald will respect both limits and use the smaller of the two values.

      The first pair defaults to 10% and the second to 15% of the size of the respective file system, but each value is capped to 4G.

      • Max-P
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        132 months ago

        If anything I tend to have the opposite problem: whoops I forgot to set up logrotate for this log file I set up 6 months ago and now my disk is completely full. Never happens for stuff that goes to journald.

      • @wildbus8979
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        2 months ago

        It can be, but the defaults are freaking stupid and often do not work.

    • @[email protected]
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      52 months ago

      Still boggles my mind that systemd being terrible is still a debate. Like of all things, wouldn’t text logs make sense?

  • @[email protected]
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    162 months ago

    This once happened to me on my pi-hole. It’s an old netbook with 250 GB HDD. Pi-hole stopped working and I checked the netbook. There was a 242 GB log file. :)

  • zoey
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    102 months ago

    Recently had the jellyfin log directory take up 200GB, checked the forums and saw someone with the same problem but 1TB instead.

    • @[email protected]
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      2 months ago

      2024-03-28 16:37:12:017 - Everythings fine

      2024-03-28 16:37:12:016 - Everythings fine

      2024-03-28 16:37:12:015 - Everythings fine

  • Scribbd
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    62 months ago

    I recently discovered the company I work for, has an S3 bucket with network flow logs of several TB. It contains all network activity if the past 8 years.

    Not because we needed it. No, the lifecycle policy wasn’t configured correctly.

  • @[email protected]
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    62 months ago

    Windows isn’t great by any means but I do like the way they have the Event Viewer layout sorted to my tastes.

    • @[email protected]
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      32 months ago

      True that. Sure, I need to keep my non-professional home sysadmin skills sharp and enjoy getting good at these things, but I wouldn’t mind a better GUI journal reader / configurator thing. KDE has a halfway decent log viewer.

      It might also go a long way towards helping the less sysadmin-for-fun-inclined types troubleshoot.

      Maybe there is one and I just haven’t checked. XD