Install MDADM Raid 0 on running system

[gianlucarenzi]

Hello everybody!
In my last forum post (around january/february) I asked for an installation method using an already configured RAID 0 disk system and I have to thank everybody's comment.
But due to the lack of time, I switched over a single drive installation and now, after Upgrade 4 install, I really need to have a RAID System too...
I tried to use a Debian Guide and Ubuntu Guide but NONE seems to work properly. Basically I need to create a mdadm drive first (with 1 disk only), then rsync from the original drive, then update grub to boot from a md disk, then reboot and wipe all data on the original installation disk and add it to my new raid system.
One of the problems I have is my system has 4 disks (2 PATA and 2 SATA). All PATA drives have Ubuntu installation and data partition I need to keep, first SATA drive has this LMDE installation and the other SATA drive will need to be the starting SATA Raid 0 disk... I forgot to mention that sometimes the boot drive will named /dev/sda and other times /dev/sdc and the other drives will be swapped as necessary. I suppose to have a /dev/disk_by_uuid/ or similar mdadm installation but what about grub?
I hope everything it is clear enough
So any help will be very appreciated.

Sorry for my bad english.

Regards,
Gianluca

[mintybits]

Hello everybody!
In my last forum post (around january/february) I asked for an installation method using an already configured RAID 0 disk system and I have to thank everybody's comment.
But due to the lack of time, I switched over a single drive installation and now, after Upgrade 4 install, I really need to have a RAID System too...
I tried to use a Debian Guide and Ubuntu Guide but NONE seems to work properly. Basically I need to create a mdadm drive first (with 1 disk only), then rsync from the original drive, then update grub to boot from a md disk, then reboot and wipe all data on the original installation disk and add it to my new raid system.
One of the problems I have is my system has 4 disks (2 PATA and 2 SATA). All PATA drives have Ubuntu installation and data partition I need to keep, first SATA drive has this LMDE installation and the other SATA drive will need to be the starting SATA Raid 0 disk... I forgot to mention that sometimes the boot drive will named /dev/sda and other times /dev/sdc and the other drives will be swapped as necessary. I suppose to have a /dev/disk_by_uuid/ or similar mdadm installation but what about grub?
I hope everything it is clear enough
So any help will be very appreciated.

Sorry for my bad english.

Regards,
Gianluca

Let me understand this. You have linux installed on a single disk. You wish to migrate it to a RAID0 pair of disks but only have 1 other disk to use. Is that right?

As far as I know you cannot make a RAID0 with 1 disk and then expand it to 2 disks. It is a striping system and so 2 disks (or 2 partitions) are needed from the start. It isn't a mirror like RAID1.

If you have used less than half the LMDE sata disk you could make a RAID0 with the other half and half the spare sata disk. Then copy LMDE partition over, delete it and then expand the RAID0 to fill the whole of both disks.

Grub can boot a RAID0 so you would chroot into the RAID0 OS and do "dpkg-reconfigure grub-pc". You'd have to edit the fstab first so it uses the correct UUIDs. You probably want to make a non-RAID partition for swap, or perhaps you already have swap partitions on the pata disks and so don't need any more.

[gianlucarenzi]

Oops! I am sorry, I was trying to install a RAID 1 (Mirror) System, not RAID 0...
My bet...

Any help for this? Any guide?