Date: Sun, 15 Sep 2002 11:38:52 +0200 From: =?iso-8859-15?Q?Aur=E9lien?= Nephtali <aurelien.nephtali@wanadoo.fr> To: Sean Hamilton <sh@planetquake.com> Cc: hackers@FreeBSD.ORG Subject: Re: dmesg circular buffer Message-ID: <20020915093852.GA3645@nebula.wanadoo.fr> In-Reply-To: <000501c25c99$af6b6d40$911de8d8@slugabed.org> References: <000501c25c99$af6b6d40$911de8d8@slugabed.org>
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--3MwIy2ne0vdjdPXF Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, It seems that on some machines, while rebooting, the memory where the kernel message buffer is stored, is not cleaned (on my laptop it's the case). If your computer has this *bug*, doing 'dmesg' will display all messages since you powered on you computer. Otherwise, if your memory is cleaned correctly I don't know how you can recover last boot messages (maybe you could write a script which writes the content of /var/run/dmesg.boot into a file named dmesg-date.boot) I have patched 'dmesg' to add an option to choose to display all messages or only the last; if your system has the 'memory problem' I can send you the patches (it won't help you recovering old messages but for further calls to 'dmesg' if you have rebooted many many times, the display will be less confusing) I have submited those patches to a committer but he hasn't commited them yet. -- Aur=E9lien PS: when i say 'memory problem', I don't really know if it's deliberate or = not but I think it's not :p On Sun, Sep 15, 2002 at 02:24:25AM -0700, Sean Hamilton wrote: > Greetings, >=20 > As I understand, "dmesg" prints the tail end of a circular buffer stored > someplace on the root partition. Is it possible to have it read back beyo= nd > the last reboot? Occasionaly I see it do this, though I have no idea why. >=20 > In this case, I have a kernel that panicked, and am looking for clues. > Nothing in /var/log/messages... >=20 > sh >=20 >=20 > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message --3MwIy2ne0vdjdPXF Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (FreeBSD) iD8DBQE9hFUsDNsbHbt8ok8RAom/AKCg+BLUJG1O1CDZD0IDIIL5F8xc+gCghWnF wnELdzk+rOVjc+F0YW3I08M= =b6Ge -----END PGP SIGNATURE----- --3MwIy2ne0vdjdPXF-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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