Ubuntu 8.10 - Installing RAID 5 (4 disks) including a disk in use

[amazing mustard]

Hello,

I have a GA-S68SM-S2 motherboard with four SATA 3 Gb ports. Currently I have one Maxtor Diamondmax 21 STM3500630AS 500 GB attached. It is in full use and has about 70 GB free space left. I bought 3 additional identical disks to set up a RAID 5 array using software RAID, in which I would like to include the disk in use.

My question:
Is it possible to keep my data while including this disk in a software RAID 5 array? I'd hate to install everything all over again.


Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00073e1d

Device Boot Start End Blocks Id System
/dev/sda1 * 1 60075 482552406 83 Linux
/dev/sda2 60076 60801 5831595 5 Extended
/dev/sda5 60076 60801 5831563+ 82 Linux swap / Solaris

[Bachstelze]

Yes.

Basically, you can temporarily set up your RAID with one missing drive. That will allow you to copy the data from that drive to the RAID, and then you can add the last drive to your array.

Normally, to build a 4-disk RAID-5 array, you would do:


mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1

instead, do for example:


mdadm --create --verbose /dev/md0 --level=5 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdd1 missing