Robert De Mars wrote:
> I was curious if anyone knew of a good how to that explains the steps 
> for moving an existing non-raid system to a RAID 1 setup.
> 
> The system currently has an 80G hard drive running Slackware 12.1.
> 
> I would like to move the file system from the 80G hard drive to a RAID 1 
> setup using 2 x 500G drives, and then toss the 80G in the trash.
> 
> If any one knows of a document(s), I would greatly appreciate it.

Here are my notes-to-self from when I did the same thing. This was on Debian.

This should at least sketch out the general process...

    * Initial drive is in hda.
    * Installed one of the new drives in hdc.
    * I partitioned hdc with 4 primary partitions to be / (md1), /tmp 
(md2), /var (md3), and swap (md4) all with partition type 0xfd. This means 
swap will be on RAID as well. Probably would be easier to use a swap file 
rather than a swap partition, but this is how I did it.
     * Used mdadm to create md1 as RAID1 array of /dev/hdc1 with the second 
device listed as "missing" so it would come up in degraded form.
     * Did the same for md2, md3, and md4
     * Added the new arrays to /etc/mdadm/mdadm.conf
     * Mounted the new arrays for /, /tmp, and /var under /newsys/, 
/newsys/tmp, and /newsys/var
     * Copied most everything over to newsys by cd'ing to / then issuing 
"tar -c bin boot etc home mnt usr {...etc} | ( cd /newsys ; tar -xvp )". 
Where {...etc} means the rest of the directories in the root dir which I 
wanted to copy. Directories I did not copy were /dev, /proc/, /newsys, /sys.
     * Made directories dev, proc, sys under newsys as mounting points
     * Copied the basic dev files by binding / (the root) to /tmproot to 
get at the actual dev files hidden by the udev system, (e.g. mount --bind / 
/tmproot ), then using the same tar pipe to copy from /tmproot/dev to 
/newsys/dev. I don't know how important this step is, but seems like it 
might be necessary to hold things until udev comes up on boot.
     * Edited /newsys/etc/fstab to switch to the new arrays
     * Edited /newsys/boot/grub/menu.lst to direct grub to (hd1,0) for 
root, and change the kernel params to say root=/dev/md1
     * Ran in grub shell: "root (hd1,0) ; setup (hd1) ; setup (hd0)" so 
both drives mbr's would look to /dev/hdc1 for the root filesystem to boot. 
At this point I could still boot back into the old system by changing grub 
to root (hd0,0). (Which I did several times since I forgot to create 
directories for proc and sys without which the boot up failed.
     * Once booting into the new arrays works well, install second new 
drive in /dev/hda and fdisk it to make it match the other drive and set the 
types to 0xfd (raid element)
     * I hot-added the hda partitions into the arrays (e.g. mdadm -add 
/dev/md1 /dev/hda1, etc.) and watched while it synched everything.
     * I added the hda partitions into /etc/mdadm/mdadm.conf
     * I ran grub and did a root (hd0,0) ; setup (hd0) so that grub on each 
mbr would look to it's own drive for the root system. Then if one drive 
dies completely I should still be able to boot off the other.
     * I reboot a couple times to make sure everything would come up ok.