release notes addition for raidtools2 -> mdadm migration

[Martin Michlmayr <tbm@cyrius.com>]

* Matthijs Mohlmann <matthijs@cacholong.nl> [2005-05-31 19:55]:
> Updated release notes.
> 
> I've also tested the stuff.

debian-doc: below is a brief note about the raidtools2 -> mdadm
migration written by Matthijs Mohlmann and slightly modified by
myself.  Please stick this in the release notes.

-- 
Martin Michlmayr
http://www.cyrius.com/

4.6.2 Upgrading from raidtools2 to mdadm

raidtools2 is not maintained by its upstream developers anymore and has
been replaced by the package mdadm.  mdadm is single program that can
perform almost any task without having a configuration file and it does
not use one by default.

In the following, some upgrade hints for users of raidtools2 are given:

If your RAID array was created on a 2.2 Linux kernel patched with RAID
support, the superblock was created incorrectly, or at least in an
incompatible way to 2.4 and later kernels.  In order to fix this problem,
you have to execute the following two commands:

    mdadm --examine --sparc2.2
    mdadm --assemble --update=sparc2.2

As mentioned above, mdadm can work without configuration file in many
situation.  If you use a kernel that automatically configures the RAID
array you, can skip this paragraph -- you merely have to install the
mdadm package and the RAID will be detected during the boot process.
The standard kernels in Debian have support for the configuration of
RAID arrays on boot.  You also need to make sure that the partitions are
set to type "Linux raid autodetect" (id fd) with the following command:

    fdisk -l <device_in_array>

If you have a mixed setup with some RAID arrays that are auto-configured
and some that are not, you have to create a configuration file.

To migrate from the configuration /etc/raidtab (raidtools2) to
/etc/mdadm/mdadm.conf (mdadm) please execute:

    echo 'DEVICE /dev/hd*[0-9] /dev/sd*[0-9]' > /etc/mdadm/mdadm.conf
    mdadm --examine --scan >> /etc/mdadm/mdadm.conf

This commands will generate a configuration file with the existing arrays
on the system.

You should also make sure that the RAID arrays are automatically started
on boot.  Check the file /etc/default/mdadm to see if the variable
AUTOSTART is set to true.