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Re: linux software RAID with hot-swap hardware

:-> "Russell" == Russell Coker <russell@coker.com.au> writes:


    > I've written a document on using Linux software RAID with hot-swap SCSI 
    > hardware.

nice doc, just a little comment about booting:

    > *Booting*

    > To make a RAID-1 device bootable you first have to use fdisk to
    > set the bootable flag on both the partitions for the root file
    > system (if one disk is removed you want 
    > the other disk to be bootable). 

...make this in bold, I was bitten by it :)
Also, and this is probably specific to my hardware (compaq ml530,
which has 2 scsi hosts), to boot from the right-side disks you have to
tell the bios to use the second scsi host. Quite annoying.

    > Then you have to to configure LILO with the root=/dev/md1 and
    > boot=/dev/md1 lines to configure the root file system as the
    > boot device (NB if you use a RAID device 
    > other than /dev/md1 for the root file system then adjust the
    > LILO configuration accordingly. The LILO configuration is in
    > /etc/lilo.conf, to apply the changes run the 
    > lilo command with no parameters.

    > Finally you have to use the install-mbr command to set up a boot
    > block that the BIOS can run to load the LILO block, use the
    > following commands: 

    > install-mbr /dev/sda
    > install-mbr /dev/sdb

    > This installs the Debian MBR on both hard drives so that
    > whichever drive is removed the other has a boot loader that can
    > then load LILO to boot Linux. 

Instead of install-mbr, I used the following line in lilo.conf:


According to the documentation of lilo, this shouldn't be necessary,
but apparently either the funcionality or the docs are buggy. Without
that line I couldn't boot at all from the second disk, or from any
disk that weren't formatted during the initial installation process
(note that after installing the first machine, I just replicated the
others by swapping the disks around and having raid regenerate the

Hope this is useful for you



 Pierfrancesco Caci | ik5pvx | mailto:p.caci@tin.it  -  http://gusp.dyndns.org
  Firenze - Italia  | Office for the Complication of Otherwise Simple Affairs 
     Linux penny 2.4.20-ac2 #1 Fri Jan 17 18:10:25 CET 2003 i686 GNU/Linux

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