> 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.
Or perhaps more succinctly? Index: dmesg.8 =================================================================== RCS file: /cvs/src/sbin/dmesg/dmesg.8,v retrieving revision 1.15 diff -u -p -u -r1.15 dmesg.8 --- dmesg.8 13 Jan 2015 10:07:58 -0000 1.15 +++ dmesg.8 13 Mar 2015 03:37:45 -0000 @@ -45,6 +45,8 @@ .Nm displays the contents of the system message buffer. It is most commonly used to review system startup messages. +On some systems the message buffer can survive reboot and be +retained (in the hope of exposing information from a crash). .Pp The options are as follows: .Bl -tag -width Ds