Don't touch your current boot disk
All actions described below should not be performed to
your current boot disk, or else you will not be able to boot again.
Find the name of your boot disk: mount.
Somewhere at the top you see a line
/dev/sdd1 on / ext3 (...)
so that is a disk we are not going to format for now.
Don't touch your data disks
If there still are any disks with valueable data in the system,
all actions described below should not be performed to
that particular data disk, or else you will loose your
music and photographs.
(I told you in the previous chapter to put that disk in a save place).
What disks are connected ?
With fdisk -cl we get an idea where the disks are,
and how large they are. (older versions don't want the 'c').
Boot partitions
First choose 2 disks for the mirrored boot partition
(tip: choose the 2 most reliable disks, or the 2 largest,
probably also being the newest).
Just 150 MBytes can hold 3 to 5 kernels and other boot-stuff.
So create a first partition of 150 Mbytes on those 2 disks.
Data partitions
The other partitions will be paired to create mirrored partitions,
suitable for a logical volume.
Fill in all disks (including the data disks you've hidden away)
in the following form and press OK.
For the moment this is a script,
computing with a poor-man's version of dc (not arbitrarily accurate,
works in floats), with test in integer only. Will be fixed later.
For now: try some more rounded values if it fails.
Enter fdisk -l to get the names (sda, sdb, ...) and corresponding sizes
for each disk.
Correct for the boot-partitions you have already claimed:
just subtract the amount of MBytes before entering
the numbers in the form below.
Please use names of the disks (sda, sdb) (no fancy names)
since the computation script is very simple.
Fdisk and mirroring
Now you should have a table with disk names and suggested partition sizes.
Now for each disk (except for your boot- and saved-data disks), do the following:
Note: you did calculate the size of the boot partition before,
and adjusted the total available remaining disk-size for these partitions ?
Great !
Mirroring
Now you have every partition twice (on different disks).
They now must be combined to mirrored devices (md's).
The smallest combination (boot device about 50 MBytes) is already made md0.
Create the other md's (md1 up to md9 in no particular order) like this:
combine 2 equally sized partitions with commands like:
mdadm --create /dev/md1 --level=1 --raid-disks=2 --assume-clean /dev/sdc2 /dev/sdd2
Of course, use the devices (sdc2, sdd2) appropriate for your configuration.
And increment the md number each time.
Finish with the command
update_mdadm.cfg.sh
to save the currend md configuration in /etc/mdadm.cfg.
Some md devices cannot be made yet, because
one of the partitions must be made later on the currently occupied install disk,
or one of the partitions must be made later on a disk that still contains
valuable data at this moment.
Just ignore those ms's for the moment, and continue with the md's
that can be made.
Later (when those disks are available) the md's can be created,
and the md's can be added to the volume group afterwards.
