[CentOS] CentOS LiveCD on USB

Tue Nov 19 18:17:47 UTC 2013
m.roth at 5-cent.us <m.roth at 5-cent.us>

Glenn Eychaner wrote:
> I had already gotten rid of rghb. The grub2 entry on the key for booting
> the LiveCD reads:
>
> menuentry "CentOS 6.4 Live" {
> set root=(hd0,1)
> linux /CentOS-Live/isolinux/vmlinuz0 root=UUID=A352-6D7C ro liveimg
> nodiskmount nolvmmount selinux=disabled live_dir=/CentOS_Live/LiveOS
> initrd /CentOS-Live/isolinux/initrd0.img
> }
>
> The contents of the LiveCD appear in /CentOS_Live as one would expect. The
> boot fails right after a device scan (obvious by tens of lines listing
> "ataN:", "scsiN:", "sd 0:0:0:0:", etc.) with the "No root device" error
below.
>
> In the rdshell, /dev/sda shows up as the internal system hard drive rather
> than the USB key. The USB key does not show up as /dev/sdb nor any
> other device that I can find. Finally, I looked in /dev/mapper (duh); it
> contains /dev/mapper/control, but no /dev/mapper/live-rw.
>
That's odd, that the internal shows up as sda. However, the obvious two
things: first, and esp. if the systems sees the internal as a, is that
this won't work. at all - the grub entry is completely wrong - assuming
that's a grub.conf. If so, you want
title CenOS 6.4 Live
   root (hdx,0)
   kernel /CentOS-Live/isolinux/vmlinuz0 root=<huh0> <huh1> NO_LVM
selinux=disabled  <huh2>
   initrd /CentOS-Live/isolinux/initrd0.img

Notes:
huh0: are you sure that's the actual UUID of the flash drive? You might
check /dev/disk/by-id
huh1: Not familiar with nodiskmount
huh2: Dunno bout the live_dir... does a quick google...OH! Of course it
won't work - you're using
        grub2, which CentOS doesn't support yet (and I hope NEVER, EVER
WILL).

        mark

-- 
grub2 MUST DIE!!!