by Linux software RAID – quick howto.
Basic steps:
1) create partitions using cfdisk or fdisk (set them to MSDOS type with parted beforehand if required)
2) Change partition type to Linux Raid autodetect
3) Create RAID
4) Format RAID devices
Show partitions with ‘fdisk -l’
Device Boot Start End Blocks Id System
/dev/sdb1 * 63 257039 128488+ fd Linux raid autodetect
/dev/sdb2 257040 11968424 5855692+ fd Linux raid autodetect
/dev/sdb3 11968425 19776014 3903795 fd Linux raid autodetect
/dev/sdb4 19776015 1953525167 966874576+ 5 Extended
/dev/sdb5 19776078 1953525167 966874545 fd Linux raid autodetect
Duplicate partitions /dev/sdb[x] -> /dev/sda[x]
sfdisk -d /dev/sdb | sfdisk /dev/sda
Create RAID devices:
mdadm --create /dev/md0 --level=1 --metadata=0.90 --raid-devices=2 /dev/sd[ab]1
mdadm --create /dev/md1 --level=1 --metadata=0.90 --raid-devices=2 /dev/sd[ab]2
mdadm --create /dev/md2 --level=1 --metadata=0.90 --raid-devices=2 /dev/sd[ab]3
mdadm --create /dev/md3 --level=1 --metadata=0.90 --raid-devices=2 /dev/sd[ab]5
Result:
root@sysresccd /root % fdisk -l
Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000dea8b
Device Boot Start End Blocks Id System
/dev/sda1 * 63 257039 128488+ fd Linux raid autodetect
/dev/sda2 257040 11968424 5855692+ fd Linux raid autodetect
/dev/sda3 11968425 19776014 3903795 fd Linux raid autodetect
/dev/sda4 19776015 1953525167 966874576+ 5 Extended
/dev/sda5 19776078 1953525167 966874545 fd Linux raid autodetect
Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00013729
Device Boot Start End Blocks Id System
/dev/sdb1 * 63 257039 128488+ fd Linux raid autodetect
/dev/sdb2 257040 11968424 5855692+ fd Linux raid autodetect
/dev/sdb3 11968425 19776014 3903795 fd Linux raid autodetect
/dev/sdb4 19776015 1953525167 966874576+ 5 Extended
/dev/sdb5 19776078 1953525167 966874545 fd Linux raid autodetect
Disk /dev/md0: 131 MB, 131465216 bytes
2 heads, 4 sectors/track, 32096 cylinders, total 256768 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md1: 5996 MB, 5996150784 bytes
2 heads, 4 sectors/track, 1463904 cylinders, total 11711232 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md2: 3997 MB, 3997368320 bytes
2 heads, 4 sectors/track, 975920 cylinders, total 7807360 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/md3: 990.1 GB, 990079418368 bytes
2 heads, 4 sectors/track, 241718608 cylinders, total 1933748864 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
root@sysresccd /root %
So your partitions now map to RAID devices as follows:
/dev/sda1 -> /dev/md0
/dev/sda2 -> /dev/md1
/dev/sda3 -> /dev/md2
/dev/sda4 -> /dev/md3
Show output of RAID build progress
cat /proc/mdstat