What kernel parameter do I need to modify in the source to allow a
larger dmesg buffer? I have a lot of boot messages and I currently
loose about 10-20 lines immediately and they can not even be seen in
/var/log/dmesg because that file gets dumped after those lines are
already gone. Thanks to anyone who can help.
Jordan Breeding
On Mon, Oct 01, 2001 at 06:46:01PM -0500, Jordan Breeding wrote:
> What kernel parameter do I need to modify in the source to allow a
> larger dmesg buffer? I have a lot of boot messages and I currently
> loose about 10-20 lines immediately and they can not even be seen in
> /var/log/dmesg because that file gets dumped after those lines are
> already gone. Thanks to anyone who can help.
>
Does dmesg wrap around before klogd can grab the info? Check
/var/log/kern.log (in debian, your filename may vary...) to see...
Mike
Jordan Breeding wrote:
>
> What kernel parameter do I need to modify in the source to allow a
> larger dmesg buffer? I have a lot of boot messages and I currently
> loose about 10-20 lines immediately and they can not even be seen in
> /var/log/dmesg because that file gets dumped after those lines are
> already gone. Thanks to anyone who can help.
That would be a #define of LOG_BUF_LEN in linux/kernel/printk.c.
Be sure to keep it a power of 2.
There have been several patch files for this on the kernel
mailing list, but it's easy enough to DIY.
~Randy
> What kernel parameter do I need to modify in the source to allow a
> larger dmesg buffer? I have a lot of boot messages and I currently
> loose about 10-20 lines immediately and they can not even be seen in
> /var/log/dmesg because that file gets dumped after those lines are
> already gone. Thanks to anyone who can help.
No command line paramter. Go into linux/kernel/printk.c and increase the
value of LOG_BUF_LEN. It must be a power of two.
Jordan Breeding wrote:
>
> What kernel parameter do I need to modify in the source to allow a
> larger dmesg buffer? I have a lot of boot messages and I currently
Note the -s flag.
rgds,
tim.
DMESG(8) DMESG(8)
NAME
dmesg - print or control the kernel ring buffer
SYNOPSIS
dmesg [ -c ] [ -n level ] [ -s bufsize ]
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