[sf-lug] About USB partitioning and formatting

[jim]

many thanks. i am reading and rereading, 
will reply. 


On Mon, 2010-01-04 at 16:42 -0800, Ken Shaffer wrote:
> Hi Jim, Here's some notes on initial ram disks -- using them has
> simplified in the last few years.
> Ken
> 
> Initial Ram Disk Notes
> 
> Examining the initrd from a 4g stick and one from a usb hard disk
> showed no significant difference.  The usb hard disk initrd worked
> in booting a 4g stick.  My previous booting problems I now attribute
> to wrong grub devices.
> 
> The initrd may be examined with the cpio command on post FC3 systems.
> Uncompress the initrd with "gzip -cd" or "zcat", and pipe to cpio to
> list the contents.
> zcat initrd... |cpio  --list
> 
> Older systems use the loopback device:
> mkdir temp ; cd temp
> cp /boot/initrd.img ./initrd.img.gz
> gunzip initrd.img.gz
> mount -t ext -o loop initrd.img /mnt/initrd
> ls -la /mnt/initrd
> 
> Newer systems just unzip and use cpio to create files in a directory:
> mkdir myird
> cd myird
> zcat /boot/initrd.img-2.6.31-16-generic |cpio -iv --make-directories
> 
> From the top level of the initrd directory, you may recreate the
> initrd by:
> find ./ |cpio -H newc -o >../myrd
> cd ..
> gzip myrd
> 
> The newc format (-H newc) is required to boot, the default (bin) fails
> to work.
> 
> In the init script on the top level, I changed the initial init
> message, and started a /bin/sh just after the depmod -a in init. There
> was a pause of 20 seconds, then the shell became active, which allowed
> me to look around the live ramdisk directories. When I exited, the
> boot sequence continued. If you remove the "quiet" on the grub.cfg
> (menu.lst) kernels, you can see the progress of the boot -- The lower
> case "ok"s are from the initram scripts, and the upper case "OK"s are
> from the root file system scripts.
> 
> The initrd contents varies depending upon the type of system you have.
> The Fedora Core systems tend to have directories like /proc and /sys
> set up, but Ubuntu (9.04 at least), creates such directories on the
> fly from the initial scripts.  In either case, the first thing run
> is /init.
>