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-   -   "No root device found" error in FC14 after upgrade from ...97 to ...100 kernel (http://www.linuxquestions.org/questions/fedora-35/no-root-device-found-error-in-fc14-after-upgrade-from-97-to-100-kernel-911377/)

PaulFC5 11-01-2011 09:18 PM

"No root device found" error in FC14 after upgrade from ...97 to ...100 kernel
 
In the recent query "How to login as root on Fedora 14 from console"
John VV replied:

Quote:

Originally Posted by John VV (Post 4511989)
but please do not use that "pam" hack
there ARE VERY big problems with that .
A lot of tools WILL NOT WORK from root if you do .

both fedora AND the Gnome desktop
killed off the root gui boot
-- for GOOD REASONS ---

AAMOI & FMI what are those good reasons?

I ask because, apart from su -, I've been using the "commentingoutline2 in /etc/pam.d/password" hack to get at "root" for months and have just had an FC14 winDoze"BSOD"equivalent - ie after the usual 10 or 15 second's worth of hdd "concretemixer" :) noises it would get to the "F" logo and "hang" - no mouse pointer would appear and it would get no further.

The cause, I think, was that I'd been shuttling back and forth from my user account to root trying to alter/freeup the @#$% permissions when suddenly neither password (root or user) was accepted - and when rebooting it just "hung".

I "solved" this by downloading (from cyberciti.biz) the "full" installDVD to get at the "rescue" bizzo - the "stripped" down 1xCD (ex a magazine's coverDVD (Feb APC ex Oz)) that I'd installed offof didn't seem to have the "rescue" gubbins in it.

The rescue seemed to have to rewrite SElinux labels or something like that and then it all seemed to work OK again - am using it now.

Except that after the "autoupgrade" it just did to the ...100 kernel it seems to come up with:
"No root device found
Boot has failed, sleeping forever."
And I have to go back to the 2.6.....97 kernel again to get it to boot up.

Is it the "pam hack" causing this or is it perhaps my possibly "fraying" sdd? - an excellent (AShampoo) winDoze app that I use seems to show slightly/slowly declining sdd health.

A good/timely reminder to back up everything important! - onto my USB external hdd.
Even considered, for a day or so, "going to the cloud" - ie using my ISP's server for in and out emails - only need a browser for that :)

TIA
Paul W

RockDoctor 11-02-2011 01:18 PM

Sometimes all it takes is re-creating the initramfs.
Code:

man dracut
for more info, and, if that's not enough,just reply here

PaulFC5 11-03-2011 03:42 PM

Thanks muchly for that RockDoctor

Am not quite "computerliterate" enough to get it to work properly, even after reading the man and the Fedora pages on it.

Does one just use the kernel number (which (the nonbooting one) = 2.6.35.14-100) or the whole /vmlinuz/... bizzo from the grub "kernel..." line - which, I spose, is both the <image> and the <kernel>?

ie do I run (from root obviously):
Quote:

dracut /vmlinuz-2.6.35.14-100.fc14.i686 ro root=/dev/mapper/vg_asusamd64x2boxsu120611-lv_root
?

And how come it's obviously doing it OK (ie setting up the initramfs) in the ...-97 kernel bootup process?
Is it (possibly) worth clearing the -100 kernel and then re-installing it??

TIA
Paul W

PaulFC5 11-03-2011 04:17 PM

My idiocy - for some reason the last two lines of the -100 kernel entry in grub.conf had gotten "commented out".

Fixed now and working OK.

Mea culpa :o

RockDoctor 11-03-2011 06:00 PM

Glad it's working. The only reason I didn't give an example is that I always have to read the man page when I want or need to recreate the initramfs file. After reading your penultimate post, I decided to see if any of my bash histories include an actual example, and, lo and behold, one does (but I had to chroot into an older installation to find it).
Code:

dracut -H `uname -r` myinitramfs-`uname -r`
`uname -r` provides the version of the currently running kernel; apparently I was aiming for an initramfs file that just included the components needed to boot my system. For some reason, size mattered.

PaulFC5 11-04-2011 01:37 AM

Another command to put into my cranial harddrive - or my sda (to be pedantic) I spose :)
Still looks quite tricky to use though!
There's always some new thing to learn in linux - and so many good people/uplines on LQ :hattip:

Thanx again for your help in my idiocy :o:doh:


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