On Mon, Jul 05, 2010 at 02:17:26PM -0700, Mark Knecht wrote: > On Mon, Jul 5, 2010 at 12:11 PM, Willie Wong <ww...@math.princeton.edu> wrote: > > 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. > > > In my normal booting kernel (on the system hard drive) I did push > the length up to 18. With that setting dmesg prints all the way back > to the beginning. However booting the Live CD I hit F1, it shows the > kernels, so I type >
to add to the confusion is probably the fact that the in-kernel configuration parameter is a bit-shift number, and the boot-time cmdline parameter is actually 2 to that power. So the in-kernel configuration parameter should be k (=18 in your case), and the boot-time parameter should be 2^k (=262144). Cheers, W -- Willie W. Wong ww...@math.princeton.edu Data aequatione quotcunque fluentes quantitae involvente fluxiones invenire et vice versa ~~~ I. Newton