Using live-CD to fix LILO boot

[Ron Leach]

Good afternoon,

Though I use XFCE on my netbook - and very pleased with that, by the 
way - I have been trying to also use the LiveCD to help me fix a LILO 
and RAID configuration on a desktop system.

I couldn't see how to access the main filesystems (which are XFS) on 
the desktop's SATA drives; they weren't mounted automatically by the 
LiveCD, and I don't seem to be able to edit /etc/fstab, so I'm a bit 
at sea, here.  The 'places' commands only shows the LiveCD filesystem, 
not the SATA drives.

(Skip this because this is NOT my question, but the context is this: I 
think I know what's wrong with the LILO config.  The RAID system used 
to work with /sdb and /sdc but then a separate non-raid disc failed 
yesterday.  Removing it resulted in the RAID system wanting to use its 
existing drives as /sda and /sdb instead.  I did re-configure the RAID 
/md partitions to do this, and they re-synced ok, and the system was 
working fine.  But on restart this morning, LILO doesn't recognise the 
'VFS' and I 'think' it's because LILO is still looking at /sdb and 
/sdc.  So I want to inspect the LILO config, and change it as necessary.)

Could somebody put me right?  Putting the XFCE LiveCD into the desk 
and rebooting, what should I then do for it to see the existing XFS 
partitions and mount a filesystem (even if only for inspection, that 
would be a help so I can do some checks)?

(I'm not expecting detailed RAID advice here - I'll happily ask on the 
RAID list if I need that - I just want to 'see' the existing drives 
and files using the LiveCD I already have.)

Very grateful for any pointers,

regards, Ron

[Todd And Margo Chester]

On 09/02/2011 07:12 AM, Ron Leach wrote:
>  Good afternoon,
>
>  Though I use XFCE on my netbook - and very pleased with that, by the
>  way - I have been trying to also use the LiveCD to help me fix a LILO
>  and RAID configuration on a desktop system.
>
>  I couldn't see how to access the main filesystems (which are XFS) on
>  the desktop's SATA drives; they weren't mounted automatically by the
>  LiveCD, and I don't seem to be able to edit /etc/fstab, so I'm a bit
>  at sea, here.  The 'places' commands only shows the LiveCD filesystem,
>  not the SATA drives.
>
>  (Skip this because this is NOT my question, but the context is this: I
>  think I know what's wrong with the LILO config.  The RAID system used
>  to work with /sdb and /sdc but then a separate non-raid disc failed
>  yesterday.  Removing it resulted in the RAID system wanting to use its
>  existing drives as /sda and /sdb instead.  I did re-configure the RAID
>  /md partitions to do this, and they re-synced ok, and the system was
>  working fine.  But on restart this morning, LILO doesn't recognise the
>  'VFS' and I 'think' it's because LILO is still looking at /sdb and
>  /sdc.  So I want to inspect the LILO config, and change it as necessary.)
>
>  Could somebody put me right?  Putting the XFCE LiveCD into the desk
>  and rebooting, what should I then do for it to see the existing XFS
>  partitions and mount a filesystem (even if only for inspection, that
>  would be a help so I can do some checks)?
>
>  (I'm not expecting detailed RAID advice here - I'll happily ask on the
>  RAID list if I need that - I just want to 'see' the existing drives
>  and files using the LiveCD I already have.)
>
>  Very grateful for any pointers,
>
>  regards, Ron
>  _______________________________________________
>  xfce mailing list
>  xfce(a)lists.fedoraproject.org
>  https://admin.fedoraproject.org/mailman/listinfo/xfce
>  
Hi Ron,

    The Live CD does not always mount all your stuff as it does
not cover all the controller the installation CD comes with.

    Instead, use your installation CD's rescue mode.  Here are
my notes on how to do this.  It is a bit dated, but everything
is there.  I have used it several time with success.

   I am the person who reported the "burn a DVD and destroy
your hard drive" bug to Red Hat -- they fixed it for me.  I had
to completely reinstall my hard drive twice, lilo and all.

HTH,

-T


---Lilo.Recovery.txt---

How to reinstall Lilo:

Boot into rescue mode from your first Red Hat install disk:

It should automatically detect your linux partitions and
mount them at /mnt/sysimage.

     #chroot /mnt/sysimage
     #cd /etc
     #lilo

[Ron Leach]

On 03/09/2011 03:23, Todd And Margo Chester wrote:
>       The Live CD does not always mount all your stuff as it does
>  not cover all the controller the installation CD comes with. 
OT: Incidentally, that's a bit of a shame; if the LiveCD 'could' see 
the filesystems, the Live CD could be used for 'quick adjustments' if 
it was easily to hand, and especially if the person is using XFCE/Fxx 
on a daily basis.  But that's a discussion for another day.

>       Instead, use your installation CD's rescue mode. 
I'd already found this page:

http://docs.fedoraproject.org/en-US/Fedora/14/html/Installation_Guide/ap-...

which looked pretty helpful.  But my LiveCD - which I'd used for my 
install - didn't have the Fedora 'rescue' option on initial boot.

OT again:  Would it be possible to have the Fedora rescue option on 
the Live-CD?  Would there be enough space?  I remember a discussion 
not long ago when people were discussing what could go onto the CD 
because some space had become available.  At the time, I hadn't 
realised that 'rescue' wasn't there, nor how useful it could be.

>  Here are
>  my notes on how to do this.  It is a bit dated, but everything
>  is there.  I have used it several time with success.
>
>  ---Lilo.Recovery.txt---
>
>  How to reinstall Lilo:
>
>  Boot into rescue mode from your first Red Hat install disk:
>
>  It should automatically detect your linux partitions and
>  mount them at /mnt/sysimage.
>
>        #chroot /mnt/sysimage
>        #cd /etc
>        #lilo
>  
Thanks for this.  I didn't have a Fedora install disc.  Eventually, 
just typing 'lilo' into another very basic rescue shell seemed to 
bring LILO back into life; I guess it fixed its records about which 
drives were which.

Todd, thanks for the help,

regards, Ron

[Kevin Fenzi]

On Fri, 02 Sep 2011 15:12:20 +0100
Ron Leach <ronleach(a)tesco.net&gt; wrote:

>  Good afternoon,
>  
>  Though I use XFCE on my netbook - and very pleased with that, by the 
>  way - I have been trying to also use the LiveCD to help me fix a LILO 
>  and RAID configuration on a desktop system. 
...snip...

>  Could somebody put me right?  Putting the XFCE LiveCD into the desk 
>  and rebooting, what should I then do for it to see the existing XFS 
>  partitions and mount a filesystem (even if only for inspection, that 
>  would be a help so I can do some checks)?
>  
>  (I'm not expecting detailed RAID advice here - I'll happily ask on
>  the RAID list if I need that - I just want to 'see' the existing
>  drives and files using the LiveCD I already have.)
>  
>  Very grateful for any pointers, 
Well, since Fedora/RHEL have not used lilo in a long time, I assume
this is another distro? I would suggest using rescue media for that
distro. It would be better suited to mounting things and letting you
fix lilo.

The details for how to mounting the system depend a lot. Is it lvm?
does Fedora even see the raid? 

kevin

[Ron Leach]

On 06/09/2011 16:02, Kevin Fenzi wrote:
>  On Fri, 02 Sep 2011 15:12:20 +0100
>  Ron Leach<ronleach(a)tesco.net>  wrote:
>
> > Though I use XFCE on my netbook - and very pleased with that, by the
> > way - I have been trying to also use the LiveCD to help me fix a LILO
> > and RAID configuration on a desktop system. 
>  Well, since Fedora/RHEL have not used lilo in a long time, I assume
>  this is another distro? 
Well, I would wager you never lose at the game 'Cluedo'!

Kevin, you're quite right; it is a Debian system.  I reached for the 
Fedora LiveCD simply because I use Fedora daily - by choice - and I 
really like it, and I thought that perhaps I could check some configs 
quickly to see what might be going wrong.  I just feel confident in 
using it.

>  I would suggest using rescue media for that
>  distro. It would be better suited to mounting things and letting you
>  fix lilo. 
After seeing this page

http://docs.fedoraproject.org/en-US/Fedora/14/html/Installation_Guide/ap-...

explaining that Fedora install media have a rescue facility - and 
after noticing that the LiveCD didn't - I did dig out my Debian 
install CD, and was relieved to see that it, too, does have a rescue 
entry.  Though I wasn't sure it would help with a boot problem, it did 
give a very basic shell.  I could mount the raid system and managed to 
see various config files but there didn't seem to be any LILO files. 
Out of desperation I typed lilo to see if the program itself might be 
runnable and might let me set up something and to my surprise, and 
delight, it fixed itself.

I am going to dig further so that I understand LILO, I don't want to 
be caught out again.

I'm not sure why Debian used LILO; during the original install I had 
asked for GRUB but that didn't work on a RAID 1 /boot partition (for 
some reason) but the alternative choice of LILO did work, so I had 
just let it do that.

>  The details for how to mounting the system depend a lot. Is it lvm?
>  does Fedora even see the raid?
>  
I guess from your comment that the LiveCD would not automatically 
mount the native machine's filesystems - I didn't even find an 
/etc/fstab that had any entries for the physical machines file systems 
(it only had entries for the LiveCD filesystem).

The RAID is RAID 1 (dual discs, mirrored), running XFS filesystems; 
all partitions except swap are mirrored and the mirror is exactly the 
same size, configuration, and partition make-up.  I am not sure what 
LVM is so perhaps this implies it is not LVM?

Would you have expected the LiveCD to 'see' the system?  That would 
mean entries in /etc/fstab wouldn't it?  (I am not an expert at this.)

Kevin, thanks for the advice,

regards, Ron