[ale] why Linux hurts/disappoints me more than once

[Michael H. Warfield]

On Sun, 2010-11-28 at 01:06 -0500, Narahari 'n' Savitha wrote:
> Here is where I stand.  I took all of your suggestions.
> 
> Put my Kubuntu cd, LIVE CD Session wont start.
> Put my Ubuntu cd LIVE CD session wont start
> Put the system rescue from the link one of the members was kind enough
> to
> provide, burnt cd, session starts but machine reboots.

The machine reboots?  That's weird.  What type of CPU is there in there?
Older machines with a 586 or older AMD processor could be problems with
some of the newer 686 distros like Fedora 11 and older.  What was the
precise rescue CD you downloaded (name, version, and arch)?  Maybe an
arch mismatch?

> Finally one of the old DEBIAN cd rescue mode works

I don't know precisely what my next step might be with Debian or Ubuntu
other than reach for a Fedora based distro.  There may be something
similar in the Ubuntu initramfs but newer Fedoras (11, 12, 13, 14) now
use dracut and busybox in the initramfs and has an interesting set of
emergency shell breakpoints built into the initramfs.  Booting with
something like rdbreak=mount on the shell command line will break into a
busybox shell just before it attempts to mount the root file system
while rdbreak=pre-pivot breaks just after that but before the pivot-root
(exit then returns flow of control back to the initramfs process at each
step).  There's about a half a dozen emergency shell breakouts in the
Fedora bootup from right at the initial command like processing all the
way to just before execing the real init.  But, again, I don't know what
you've got there in Ubuntu.  Maybe someone else knows that one.  I would
be very curious to know what's running just after udev has fired up but
just before it attempts to mount the root file system and see if it even
sees the partitions (you would have to mount /proc and then
examine /proc/partitions - DON'T use fdisk or sfdisk for this since they
see what's on disk and not what the kernel has recognized and has in
memory).  The error you showed in the screen shot is unlike any of the
errors in the initramfs that would indicate an inability to find the
rootfs.  In fact, I swear it almost looks like you're not loading an
initramfs at all (except it does show that md multidrive logic
initialization).

My favorite "rescue" CD for doing this kind of work is the one I
mentioned earlier, NST, or Network Security Toolkit.  It's actually a
highly customizable (been building a custom distro with it all weekend)
forensic CD that can be either a "minimal" (<600M) or full (1.4G)
desktop system.  The minimal fits on a CD and doesn't use a GUI.  The
latest flavor is 2.13 which is Fedora 13 based.  The 32 bit flavor is
i686 just like F13 so if you've got an older i586 processor, that won't
work either.  The stock ready to burn images are up at
http://www.networksecuritytoolkit.org.

> Used fdisk to delete paritions.  Then used Ubuntu Server and re
> installed
> it.  I chose guided with LVM.  As  ususal install went fine.
> 
> When machine reboots and I start up in single user mode I see the
> folloiwng
> error
> 
> http://picasaweb.google.com/savithari/LinuxStuff?authkey=Gv1sRgCJbL1PmLm5Poag&feat=directlink
> Same old VFS syncing issue.  Not sure what to do and how to fix it.
> Any
> help is appreciated.
> 
> Just cant seem to move beyond the first  screen to boot off of.
> 
> -Narahari
> On Sat, Nov 27, 2010 at 9:17 PM, Michael H. Warfield
> <mhw at wittsend.com>wrote:
> 
> > On Sat, 2010-11-27 at 20:34 -0500, K Phillips wrote:
> > > You should be able to use any bootable livecd or liveusb and mount
> the
> > > local disk.
> >
> > > If your using standard partitions, it's a few commands (sfdisk -l,
> > > mount, etc). If using LVM it gets a bit more challenging, although
> the
> > > basic idea is the same.
> >
> > Depending on the run-live, even LVM can be pretty reasonable.  NST
> does
> > an LVM start so you just need to sort out where your pieces are.
> But,
> > yeah, you still may need to go digging in pv* and lv* commands if
> you're
> > going to dig on that level. Doesn't sound like the case here,
> however.
> > This sounded like purely a partitioning issue maybe with classical
> BIOS
> > vs EFI possibly being at the heart of the problem.
> >
> > > Without knowing your drive assignments and partition layout, here
> is
> > > example commands using the first scsi/sata disk and first
> partition:
> > > sfdisk -l
> > > mount /dev/sda1 /mnt
> > > cd /mnt/
> > > ls
> > > cd bin
> > > ./grub-install /dev/sda1
> > >
> > > This makes a bunch of assumptions and shouldn't be run exactly, as
> it
> > needs to be modified for drive type, number, partition, etc. Some of
> those
> > commands are also for verification, like ls and sfdisk.
> > >
> > > On Nov 27, 2010, at 3:24 PM, "Michael H. Warfield"
> <mhw at wittsend.com>
> > wrote:
> > >
> > > > On Sat, 2010-11-27 at 15:00 -0500, Narahari 'n' Savitha wrote:
> > > >> Thank You.  If I cant even get into the OS how can I do what
> you have
> > > >> suggested.
> > > >
> > > > Boot the Ubuntu run-live and work from the CD while you diagnose
> the
> > HD?
> > > >
> > > > There's all sorts of run-live CD's out there like my favorite to
> > > > customize, the Network Security Toolkit or NST, but you should
> have
> > > > everything you need on that Ubuntu CD.
> > > >
> > > >> Is there something that I can do to get to the shell  to run
> > > >> commands ?
> > > >>
> > > >> -Narahari
> > > >
> > > > Regards,
> > > > Mike
> > > >
> > > >> On Sat, Nov 27, 2010 at 11:24 AM, Kaerka Phillips
> > > >> <kbphillips80 at gmail.com>wrote:
> > > >>
> > > >>> Based your details, this doesn't sound like a hard drive
> failure,
> > > >> but
> > > >>> instead, like there is a gpt bootsector installed rather than
> an
> > > >> mbr, or
> > > >>> other unrecognisable bootsector.
> > > >>> One way to determine this would be to use either gparted or
> fdisk on
> > > >> the
> > > >>> drive to determine the mbr/gpt type, and if you do have gpt in
> use,
> > > >> then
> > > >>> install grub2 instead of regular grub to handle this.  If it
> is an
> > > >> mbr, but
> > > >>> grub hasn't properly installed to it, you may need to do a
> > > >> grub-install to
> > > >>> change the mbr.  Another area that could be an issue is if the
> boot
> > > >>> partition or drive isn't set to active, this could cause a
> similar
> > > >> failure.
> > > >>>
> > > >>>
> > > >>> "Installed UBUNTU 10.04 server, installation went fine but
> then
> > > >> after
> > > >>> reboot I got Unable to mount root fs unknown block (0,0)."
> > > >>>
> > > >>> There really isn't enough technical details here to do much
> more
> > > >> than
> > > >>> guess, but I would also ask - why Ubuntu Server rather than
> > > >> something like
> > > >>> Mythbuntu?  (http://www.mythbuntu.org/)
> > > >>>
> > > >>> Last but not least, did you wipe out the partition table and
> mbr
> > > >> from the
> > > >>> previous windows install (was it Win7 by chance?)?  Or just
> install
> > > >> over it?
> > > >>>
> > > >>> If you've left windows partitions on the drive, this can also
> be an
> > > >> issue
> > > >>> to work around, in that you'll need to adjust how grub sees
> the
> > > >> bootsector
> > > >>> and boot partition, drive order, and where you install the
> grub
> > > >> bootloader.
> > > >>>
> > > >>> On Sat, Nov 27, 2010 at 10:10 AM, Narahari 'n' Savitha <
> > > >>> savithari at gmail.com> wrote:
> > > >>>
> > > >>>> Friends:
> > > >>>>
> > > >>>> I have this decently good machine AMD BE2400.  I have Windoze
> on it
> > > >> for my
> > > >>>> other folks at home to use as my pseudo-HTPC.  I wanted to
> convert
> > > >> that to
> > > >>>> MYTH TV SERVER(It has 2 TB of storage)
> > > >>>>
> > > >>>> Installed UBUNTU 10.04 server, installation went fine but
> then
> > > >> after
> > > >>>> reboot I got Unable to mount root fs unknown block (0,0).
> > > >>>>
> > > >>>> Cleaned out that install put the DEBIAN SQUEEZE on the
> machine.
> > > >> The
> > > >>>> installation went fine but this time also after reboot I am
> getting
> > > >> Unable
> > > >>>> to mount root fs unknown block (0,0).
> > > >>>>
> > > >>>> Before you folks say anything, this is quite a new Hard
> drive, may
> > > >> be 1.5
> > > >>>> year old, very light use.  So bad hard drive is ruled out.
> > > >>>>
> > > >>>> Any hints how I can fix this ?
> > > >>>>
> > > >>>> -Narahari
> > > >>>>
> > > > -- 

Mike
-- 
Michael H. Warfield (AI4NB) | (770) 985-6132 |  mhw at WittsEnd.com
   /\/\|=mhw=|\/\/          | (678) 463-0932 |  http://www.wittsend.com/mhw/
   NIC whois: MHW9          | An optimist believes we live in the best of all
 PGP Key: 0x674627FF        | possible worlds.  A pessimist is sure of it!
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