Hi, I am a pretty new user so please forgive any uninformed statements. I just spent a few hours trying to figure out why my dmesg displays an old kernel (May 5th), when I just compiled a new one (for recent -stable patches). I've looked pretty much everywhere and retraced every step until finally giving up and starting to compose a mail to get help. Then, when pasting my dmesg output into the mail I realized that there were multiple system messages from multiple startups in the dmesg output, and that everything was fine with my system. Now, except for a few threads from 200[367], even now that I know what I'm looking for I don't see this behaviour documented anywhere. Since there is no other record of this behaviour my knowldge is probably incomplete but attached is a patch - I borrowed some wordings from a mail from Theo[1] - that adds this information to the dmesg manpage.
Best Regards, Thomas [1] http://marc.info/?l=openbsd-misc&m=115272548814461&w=2 Index: src/sbin/dmesg/dmesg.8 =================================================================== RCS file: /cvs/src/sbin/dmesg/dmesg.8,v retrieving revision 1.15 diff -u -p -u -r1.15 dmesg.8 --- src/sbin/dmesg/dmesg.8 13 Jan 2015 10:07:58 -0000 1.15 +++ src/sbin/dmesg/dmesg.8 13 Mar 2015 03:14:45 -0000 @@ -45,6 +45,11 @@ .Nm displays the contents of the system message buffer. It is most commonly used to review system startup messages. +If the kernel finds that the +.Nm +buffer in the kernel address space is still intact after reboot, it does +not clear it, but appends to it, resulting in the output of messages from +multiple startups. This is so that crash-related data will be retained. .Pp The options are as follows: .Bl -tag -width Ds
