[wplug] Little Bo Peep Lost Her MBR...

[Poyner, Brandon]

Can you describe what happens when you try to boot from /dev/hdb?  Does
the bios say there is no operating system, do you get a 'LI' or a 'LIL'
instead of 'LILO'?  

Have you tried making a copy of the MBR, filling the partition to 90%,
and then compare the MBR to the copy?  In other words do a dd of the MBR
and pipe to md5sum, fill the partition, and then see if the md5sum is
the same afterwards.

# dd if=/dev/hda bs=512 count=1 | md5sum
1+0 records in
1+0 records out
b6c5a9e9419b31a059890ced74a009ac  -


Brandon Poyner
Network Engineer III
CCAC - College Office
412-237-3086
 
 

> -----Original Message-----
> From: wplug-bounces+bpoyner=ccac.edu at wplug.org 
> [mailto:wplug-bounces+bpoyner=ccac.edu at wplug.org] On Behalf 
> Of Hagbard Celine
> Sent: Monday, June 13, 2005 9:38 PM
> To: wplug at wplug.org
> Subject: [wplug] Little Bo Peep Lost Her MBR...
> 
> I've been having a problem with lost Master Boot Records for 
> some time.
> Lately, some work I've been doing with large files has given 
> me an opportunity
> to collect some data in connection with the phenomenon.  
> Hopefully, some of
> you folks might know what's going on?
> 
> Some system particulars:
> Motherboards: ABIT K(x)-7 type motherboards, VIA chipsets all
> Hard drives: Many models, most are Maxtors
> Kernel: linux-2.4.19 through linux-2.4.29
> C library: glibc-2.3.2
> Filesystem: e2fsprogs-1.35
> Boot Loader: lilo-22.5.x through lilo-22.6.1
> 
> Layout:
> /dev/hda1: WinCrap98
> /dev/hda2: An early linux-2.4.x system, once used for experimentation
> /dev/hda3: The template system for my distribution, has had 
> the versions above
> /dev/hda4: swap
> The boot loader on /dev/hda will boot into the systems on 
> /dev/hda2 and
> /dev/hda3, and chain to WinCrap or to the boot loader on /dev/hdb
> 
> /dev/hdb1: The root filesystem for my daily-use system; see 
> above for versions
> /dev/hdb2: /local for the daily-use system (/usr/local 
> symlinks to this)
> /dev/hdb3: /usr for the daily-use system
> /dev/hdb4: swap
> The boot loader on /dev/hdb will boot into either of two 
> kernels, one with
> SCSI emulation, the other without, otherwise identical.
> 
> The Problem:
> It appears that when /dev/hdb1 gets to approximately 90% 
> capacity, /dev/hdb's
> MBR goes bye-bye every time I shut down (the command used seems not
> significant; halt, reboot, shutdown all produce the effect).  
> The MBR on
> /dev/hda always sticks around.  Strangely enough, though, 
> when I boot into one
> of the Linux systems on /dev/hda, mount up all the required 
> partitions, and
> write a new MBR to /dev/hdb, it will hold for the next 
> reboot.  It just
> disappears again when next I shut down.
> 
> Has anyone seen anything like this, and might anyone have an 
> idea of the cause?
> 
> Many much thanks,
> Hagbard
> 
> _______________________________________________
> wplug mailing list
> wplug at wplug.org
> http://www.wplug.org/mailman/listinfo/wplug
>