Strange boot with multiple identical disks

Strange boot with multiple identical disks

[Konstantin Kudin]

 Hi everybody,

 Here is the issue. A redhat 9 linux system had 2
drives, /hda and /hdb. Then /hda started developing
bad clusters {UncorrectableError}, so I got an
identical warranty replacement drive.

 Then I hooked up the new drive as /hdc, and did a
sector by sector copy {dd if=/dev/hda of=/dev/hdc
conv=noerror,sync} Overall, I got ~2k of bad 512B
sectors.

 Then I swaped the fresh one to /hda, and put aside
the failing one. I booted, did fsck on all partitions
and also raids, and things came up fine. So far so
good.

 Now I am trying to add the failing one as /hdc, and
boot. Linux starts to display all kinds of weird
messages, and thinks that / partition was shut down
uncleanly. I just hit "reset". Then I disable /hdc via
the boot option hdc=noprobe, and things boot fine. If
I try to disable raid via raid=noautodetect, the bunch
of errors still appears and the boot is no go. Done
this several times, without /hdc things are fine, with
- all kinds of issues.

 What is the problem for linux to boot on /hda when
/hdc is detected and has almost identical setup? 
Where does it read all the garbage that starts to
screw up the boot process when /hdc is detected? I'd
like to hook up /hdc to wipe out the data there. The
drive is huge, so I'd rather wipe it out while working
then under other circumstances.
 
 Thanks!

 Konstantin

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Re: Strange boot with multiple identical disks

[Valdis.Kletnieks]

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On Thu, 12 Feb 2004 11:28:48 PST, Konstantin Kudin <konstantin_kudin@yahoo.com>  said:

>  Now I am trying to add the failing one as /hdc, and
> boot. Linux starts to display all kinds of weird
> messages, and thinks that / partition was shut down
> uncleanly. I just hit "reset". Then I disable /hdc via
> the boot option hdc=noprobe, and things boot fine. If
> I try to disable raid via raid=noautodetect, the bunch
> of errors still appears and the boot is no go. Done
> this several times, without /hdc things are fine, with
> - all kinds of issues.
> 
>  What is the problem for linux to boot on /hda when
> /hdc is detected and has almost identical setup? 

Sometimes, the LABEL= support is your enemy.  You probably have
multiple partitions with the same LABEL=, and your /etc/fstab is
picking up the "wrong" ones.  Try giving partition names instead.

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Re: Strange boot with multiple identical disks

[Konstantin Kudin]

--- Valdis.Kletnieks@vt.edu wrote:
> On Thu, 12 Feb 2004 11:28:48 PST, Konstantin Kudin
> <konstantin_kudin@yahoo.com>  said:
> 
> >  Now I am trying to add the failing one as /hdc,
> and
> > boot. Linux starts to display all kinds of weird
> > messages, and thinks that / partition was shut
> down
> > uncleanly. I just hit "reset". Then I disable /hdc
> via
> > the boot option hdc=noprobe, and things boot fine.
> If
> > I try to disable raid via raid=noautodetect, the
> bunch
> > of errors still appears and the boot is no go.
> Done
> > this several times, without /hdc things are fine,
> with
> > - all kinds of issues.
> > 
> >  What is the problem for linux to boot on /hda
> when
> > /hdc is detected and has almost identical setup? 
> 
> Sometimes, the LABEL= support is your enemy.  You
> probably have
> multiple partitions with the same LABEL=, and your
> /etc/fstab is
> picking up the "wrong" ones.  Try giving partition
> names instead.

 Thanks for the tips! At first I tried to correct
/etc/fstab (replaced LABEL=/ by /dev/hda6), but still
got the problem. Then I also edited /etc/grub.conf and
replaced LABEL by the device there, and things boot
fine now.
 
 Konstantin
 

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Re: Strange boot with multiple identical disks

[Dave Kleikamp]

Redhat mounts the file systems by label.  I believe if you modify
/boot/grub/grub.conf and /etc/fstab to use the device names (/dev/hda*)
instead of LABEL=/, etc., then it should boot properly.  After wiping
out hdc, you can change them back to the way they were.
-- 
David Kleikamp
IBM Linux Technology Center

Re: Strange boot with multiple identical disks

[Ricky Beam]

On Thu, 12 Feb 2004, Dave Kleikamp wrote:
>Redhat mounts the file systems by label.  I believe if you modify
>/boot/grub/grub.conf and /etc/fstab to use the device names (/dev/hda*)
>instead of LABEL=/, etc., then it should boot properly.  After wiping
>out hdc, you can change them back to the way they were.

It'll boot properly ONCE.  Redhat (in their ever increasing stupidity)
converts fstab to labels on every boot.  Remove kudzu and this won't
happen anymore. (or mark /etc/fstab as immutable and then NOTHING can
change it.)

--Ricky

Re: Strange boot with multiple identical disks

[Bill Davidsen]

Ricky Beam wrote:
> On Thu, 12 Feb 2004, Dave Kleikamp wrote:
> 
>>Redhat mounts the file systems by label.  I believe if you modify
>>/boot/grub/grub.conf and /etc/fstab to use the device names (/dev/hda*)
>>instead of LABEL=/, etc., then it should boot properly.  After wiping
>>out hdc, you can change them back to the way they were.
> 
> 
> It'll boot properly ONCE.  Redhat (in their ever increasing stupidity)
> converts fstab to labels on every boot.  Remove kudzu and this won't
> happen anymore. (or mark /etc/fstab as immutable and then NOTHING can
> change it.)

Or change the label to be unique on each filesystem, of course. There's 
nothing magic about the names having to be the mount points, or wasn't 
the last time I had this problem.

-- 
bill davidsen <davidsen@tmr.com>
   CTO TMR Associates, Inc
   Doing interesting things with small computers since 1979