[systemd-devel] Journalctl reading incorrect file

[John Lane]

Hello,

I've just set up a new system and have noticed a problem with journalctl
where it appears to be reading from the incorrect journal. The journal
is running and I can direct it at the correct file using -D, but I don't
understand what is happening.

There is a journal in /run/log/journal which contains events up to the
switch root. There is a journal in /var/log/journal which contains those
same events plus the events following the switch root. Events appear to
be written correctly to /var but journalctl appears to read from /run.

# ls -ld /{var,run}/log/journal
drwxr-sr-x+  3 root systemd-journal 80 Jan 14 13:50 /run/log/journal
drwxr-sr-x+ 18 root systemd-journal 19 Jan 14 13:25 /var/log/journal

$ journalctl > /tmp/journal
$ journalctl -D /run/log/journal/e4a4799a826d44d9a6887e24025d54ae >
/tmp/run_journal
$ journalctl -D /var/log/journal/9c29e192f536402e9565718f3bb04983 >
/tmp/log_journal

$ diff /tmp/journal /tmp/run_journal # same
$ sdiff /tmp/run_journal /tmp/var_journal # latter is superset

I have not customised /etc/systemd/journald.conf (it only contains
commented out settings). I have not done anything different on this
install vs others except it being on a different device.

I tried to fix it by restarting systemd-journald but it fails to restart
(and I can't get a log message to report why). I then have no journal
until I reboot.

Not sure what to do to fix this, pointers appreciated...

Some details:

# systemctl --version && uname -a
systemd 247 (247.2-1-arch)
+PAM +AUDIT -SELINUX -IMA -APPARMOR +SMACK -SYSVINIT +UTMP
+LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +ZSTD +SECCOMP +BLKID
+ELFUTILS +KMOD +IDN2 -IDN +PCRE2 default-hierarchy=hybrid
Linux xxxxxx 5.10.6-arch1-1 #1 SMP PREEMPT Sat, 09 Jan 2021 18:22:35
+0000 x86_64 GNU/Linux
(Arch Linux)