[WBEL-users] Software raid and User Mode Linux CD burning on WBEL

[Alex Tkachenko]

On Wed, 2004-08-04 at 10:58, Paul Pianta wrote:
> Alex Tkachenko wrote:
> 
> >Maybe you are right and it is supposed to be so, but on my FC2 machine
> >it is not; also I already corrected this issue on my CentOS machine and
> >I just checked WBEL machine by doing dd if=/dev/hda bs=512 count=1 and
> >comparing that to the block from hdc - the latter one clearly does not
> >have grub software on it, only some lilo stuff (maybe what has left from
> >the previous installation). Could you please check this on one of your
> >machines, if you have software raided setup?
> >  
> >
> Ok so now you have managed to get me worried. I have a WBEL machine with 
> software raid on hda and hdc. Here are some details - sorry for the 
> weird characters :\ ...
> 
> [root@trinity root]# df -h
> Filesystem Size Used Avail Use% Mounted on
> /dev/md1 3.9G 1.9G 1.9G 51% /
> /dev/md0 99M 9.1M 85M 10% /boot
> /dev/mapper/Volume00-backup
> 68G 1.6G 63G 3% /data/backup
> /dev/mapper/Volume00-isos
> 29G 5.8G 22G 21% /data/isos
> /dev/mapper/Volume00-repositories
> 49G 1.9G 44G 4% /data/repositories
> none 190M 0 190M 0% /dev/shm
> 
> -------------------------------------------------------------------------------------------
> [root@trinity root]# dd if=/dev/hda bs=512 count=1
> �м؎�|�8u
> �u�|tAʀ�|1؎м @|<t�y}�tTAU�ZRrIUuCA|��t7fL|�fD|��f�pf1 DfD
> B�rp�s
> �|�f@fD1���@��ffD|f1�4T
> f1�tT
> D
> �L ;}<T
> �ъl
> Zt
> p�۸�r*ÎH|`�1a&B|}��}��}�}��GRUB GeomHard DiskRead Error�<u��v?
> ?/
> �~}
> KK4�LL#/-U1+0 records in
> 1+0 records out
> 
> -----------------------------------------------------------------------------------------------------
> [root@trinity root]# dd if=/dev/hdc bs=512 count=1
> м؎�|�8u
> �u�|tL��|�?
> ?/
> �~}
> KK4�LL#/-U1+0 records in
> 1+0 records out
> 
> -----------------------------------------------------------------------------------------------------
> So I guess my mbr on hdc has nothing 'grub' on it? What should I do to 
> fix this situation? What is that 'GeomHard DiskRead Error' doing in 
> there on my hda?
You are absolutely right, there's no a boot loader in your hdc's MBR
What you should see there, should be very similar to the contents of
/boot/grub/stage1, short of partition table which is at the end and some
other bits, don't remember exactly, but you could read about it here -
http://www.uruk.org/orig-grub/technical.html

To put the boot loader onto the second drive, you start the grub shell
and use commands suggested here earlier:

grub> device (hd0) /dev/hdc

grub> root (hd0,0)
 Filesystem type is ext2fs, partition type 0xfd

grub> setup (hd0)
 Checking if "/boot/grub/stage1" exists... no
 Checking if "/grub/stage1" exists... yes
 Checking if "/grub/stage2" exists... yes
 Checking if "/grub/e2fs_stage1_5" exists... yes
 Running "embed /grub/e2fs_stage1_5 (hd0)"...  16 sectors are embedded.
succeeded
 Running "install /grub/stage1 (hd0) (hd0)1+16 p (hd0,0)/grub/stage2
/grub/grub.conf"... succeeded
Done.

I found this to be very interesting reading (for the purpose of
explanation of the above skip to step 25):

http://togami.com/~warren/guides/remoteraidcrazies/


> any ideas?
> 
> pantz

Cheers,
Alex