Hi,

I have a working Ubuntu 6.06 Server machine. /dev/hdd is full of warm, juicy data, and contains all the important partitions of the system.

/dev/hda is a brand new completely empty drive that is identical in every way to /dev/hdd except for the lack of warm, juicy data.

I want to create a RAID1 setup, so that the two will mirror each other and I will have my redundant copy of all the data.

The problem: While I can create a new RAID using mdadm, that appears to require that I destroy all the data on the partitions. I've found a bunch of "convert your live machine" tutorials, and I have perfectly good backups of everything, but I'm hitting a couple of roadblocks: I don't have and can't find tools like mkraid and the rest of the raidtools and raidtools2 packages, and I don't see how to make mdadm do the job for me.

I *could* copy all the files onto a *third* drive (an external USB drive), boot onto that and use it for the server while I wipe the two internal drives and re-create them as RAID devices, but I'm hoping not to do that. That's my last-resort plan.

So, anyone done this before with Ubuntu? Anyone have some suggestions for how to make it work, or where to get the raidtools package so I can follow along the existing "converting your system to use RAID" tutorials?

Hi

For that to work, you need to start the raid in a degraded mode. That means as if it had two disks, but one crashed so you only have one.

It's explained here:
http://tldp.org/HOWTO/Software-RAID-HOWTO.html

Forget about raidtools and other commands - it's old. It's all done with the mdadm command.

That tutorial is one of the ones I've already looked at, and it uses mkraid and the other raidtools commands.

It tells me a whole lot about how to do what I want in theory, but in practice it doesn't tell me *how to use mdadm to actually create the degraded RAID*, and I'm having serious trouble finding how to make that work through the manual.

I did it some time ago, but I don't think I can recall all the steps. But I'll try:

- with fdisk I changed the partition type to "fd" - linux raid autodectect.
- then mdadm to create a broken mirror
- finally add the second disk with mdadm

All I used was that guide. It was a problem it had all that outdated information, but after a while I learned how to skip it.

It seems to be a lot harder if you want to boot from that disk. Then you do have to read a lot