Re: [gentoo-user] CD boot - dmesg buffer depth option?

[Willie Wong]

On Mon, Jul 05, 2010 at 09:16:14AM -0700, Mark Knecht wrote:
> I'm trying to capture the full boot log when booting from the Gentoo
> install CD but it seems the buffer isn't deep enough to get the whole
> thing. Is there by chance a command line option that will increase the
> depth of what's captured by dmesg so that I can get all the way back
> to the beginning?

pass the following parameter to the kernel on GRUB/LILO:

log_buf_len=n

where n is a power of two. By default it is 16384. You can change it
to 131072 (= 2^17) to get a much larger kernel log ring buffer. If you
put in something that is not a power of two, the kernel will ignore
the option. 

You may also have to pass an additional parameter to dmesg to read the
early messages: look at 'man dmesg' and the -s flag. 

Cheers, 

W
-- 
Willie W. Wong                                     wwong@××××××××××××××.edu
Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire 
         et vice versa   ~~~  I. Newton