supervision - discussion about system services, daemon supervision, init, runlevel management, and tools such as s6 and runit
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From: yianiris <>
Subject: Re: Update early logger logging path after remounting root as rw
Date: Sun, 6 Sep 2020 13:36:25 +0300
Message-ID: <> (raw)
In-Reply-To: <>

The way I understand the importance of the catch-all log is to be able
to debug the system that fails to boot.  It is writing a log in /run
even before a real filesystem is mounted.  At this point the system
should give access to this file even if root is not mounted as rw yet.
There may be many ways to have this copied to a root fs, which means it
is already mounted rw, and by this time it seems as the system doesn't
have a problem booting, so this log is of little use to getting it to boot.

In 66 this is written as /run/66/log/0/current, and I have user/root
copy it after a shell is executed, this helps when I would change
something and it is not booting right on the next boot, I can compare
the before after.  Part of 66 booting procedure is to activate tty12 as
early as possible, instead of the insecure sulogin that appears in
runit.  From tty12 you can read that log and mount things manually and
change/fix what is wrong.  You can also decrease/increase verbosity in
that log.  tty12 is a special setup in 66 where root can't login, only a
user can, a security measure I find as a great idea.

If tty12 isn't accessible, that means the uncaught-log isn't, and I
don't think there is anything in the system that could have copied that
log into something else.  So, if you can have it copied and saved is
usually when you don't need it, but when you do need it it can't be
copied.  I hope this makes sense to someone other than me :)

  reply	other threads:[~2020-09-06 10:36 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-05 15:46 Rio Liu
2020-09-05 19:45 ` Laurent Bercot
2020-09-05 20:26   ` Rio Liu
2020-09-05 20:50     ` Samuel Holland
2020-09-06 10:36       ` yianiris [this message]
2020-09-06 15:53         ` Rio Liu
2020-09-05 20:43 ` Casper Ti. Vector

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