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WinEunuuchs2Unix
Asked: 2018-02-03 17:33:54 +0800 CST

Why does `journalctl --list-boots` only show the current boot? [duplicate]

  • 772

My kernel update crashed this morning and I had to boot to an older kernel. I wanted to see the journal log for the crashed boot so used:

journalctl --list-boots
0 336aa03f15d3443d95e079ad17b6dc77 Fri 2018-02-02 05:49:03 MST—Fri 2018-02-02 17:57:50 MST

It's only showing the current reboot on the older kernel not the kernel update(s) that crashed a few times 10 minutes before.

How can I get persistence across reboots to view previous boot journals?

boot kernel systemd systemd-journald

1 Answers

  1. Best Answer

    Reported as a bug that's an undocumented feature

    There is a bug report filed on this topic. Because rsyslog already maintains multiple boot journals in /var/log/syslog and syslog.1, .2.gz, .3.gz... syslog.7.gz the developers felt keeping extra journalctl logs would waste disk space.

    The bug report states on January 3, 2018 that for new installs rsyslog will no longer be the default and that journalctl will keep multiple boot data logs.

    Create multiple boot logs without reinstalling Ubuntu

    Most of us won't do a new install so to enable multiple journalctl boot logs use:

    sudo mkdir -p /var/log/journal
sudo systemd-tmpfiles --create --prefix /var/log/journal
Cannot set file attribute for '/var/log/journal', value=0x00800000, mask=0x00800000: Operation not supported

    According to this github report the warning message on attributes can be ignored.

    Interesting new flag s instead of the familiar x (executable bit) in the file permissions of the newly created directory:

    $ ll /var/log/journal
total 8
drwxr-sr-x+  2 root systemd-journal 4096 Feb  2 18:18 ./
drwxrwxr-x  15 root syslog          4096 Feb  2 18:18 ../

    Update 3 weeks later

    $ journalctl --list-boots
-15 58a9e56135564cd8a52d547b19e76bf5 Fri 2018-02-02 18:34:35 MST—Fri 2018-02-02 23:07:14 M
-14 3514e056440341b1b6e5f03d109681bc Sat 2018-02-03 06:05:12 MST—Sat 2018-02-03 08:07:44 M
-13 0d1a32dc275348589f5ecdc72180c018 Sat 2018-02-03 08:08:05 MST—Sat 2018-02-03 08:08:34 M
-12 74159b593f3a401589ee6bd78e31684b Sat 2018-02-03 08:08:51 MST—Sun 2018-02-04 08:32:09 M
-11 4b394a9aad584ab2bfabe3b77eeed78f Sun 2018-02-04 08:32:26 MST—Mon 2018-02-05 16:54:02 M
-10 8e461ed2593c4fd896ca3b71eb3c0fba Mon 2018-02-05 16:54:34 MST—Tue 2018-02-06 03:54:30 M
 -9 ec7ba0e4dfe241c0b9c978d278fcca6d Tue 2018-02-06 03:54:47 MST—Tue 2018-02-06 16:25:02 M
 -8 b5c110267c214c38b63d0a367197d118 Tue 2018-02-06 16:25:19 MST—Thu 2018-02-08 16:49:03 M
 -7 75c3b117ac6a4de984dc3ced15edb7f8 Thu 2018-02-08 16:49:22 MST—Fri 2018-02-09 03:51:09 M
 -6 7338bd1007bc42dda5c8667eeefe1a59 Fri 2018-02-09 03:51:26 MST—Fri 2018-02-09 16:55:52 M
 -5 4b6cd0121327454ca3db035c7ed42df6 Fri 2018-02-09 16:56:09 MST—Sat 2018-02-10 07:55:14 M
 -4 0d56207f9ec0405ca3a3fd638334de2f Sat 2018-02-10 07:55:32 MST—Mon 2018-02-12 22:16:05 M
 -3 0f230cc546fd4aec8f5233e0074ab3e1 Tue 2018-02-13 03:57:20 MST—Wed 2018-02-14 22:58:56 M
 -2 c0d2c0141dd840cbab75d3c2254f8781 Wed 2018-02-14 22:59:13 MST—Sat 2018-02-17 22:46:14 M
 -1 aafb2573a6374e019a7165cb8eee74a0 Sun 2018-02-18 06:02:03 MST—Mon 2018-02-19 04:16:36 M
  0 8462f1969c6f4d61973e7e245014b846 Mon 2018-02-19 04:16:53 MST—Wed 2018-02-21 04:07:07 M

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