sda   sdb   sdc   sdd
.---. .---. .---. .---.  <-- GRUB (4x)
| 1 | | 1 | | 1 | | 1 |  /boot, RAID1
|---| |---| |---| |---|
| 2 | | 2 | | 2 | | 2 |  swap, RAID10
|   | |   | |   | |   |
|---| |---| |---| |---|
| 3 | | 3 | | 3 | | 3 |  /tmp, RAID10
|   | |   | |   | |   |
|---| |---| |---| |---|
| 4 | | 4 | | 4 | | 4 |  /, RAID5
|   | |   | |   | |   |
|   | |   | |   | |   |
  .     .     .     .
  .     .     .     .
  .     .     .     .
|   | |   | |   | |   |
`---' `---' `---' `---'


# fdisk -l /dev/sda
Disk /dev/sda: 1500.3 GB, 1500301910016 bytes
255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 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

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *          63      401624      200781   fd  Linux raid autodetect
/dev/sda2          401625     8418059     4008217+  fd  Linux raid autodetect
/dev/sda3         8418060    16434494     4008217+  fd  Linux raid autodetect
/dev/sda4        16434495  2930272064  1456918785   fd  Linux raid autodetect

# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md1 : active raid10 sdd2[3] sdb2[1] sdc2[2] sda2[0]
      8016128 blocks 64K chunks 2 far-copies [4/4] [UUUU]

md2 : active raid10 sdd3[3] sdb3[1] sdc3[2] sda3[0]
      8016128 blocks 64K chunks 2 far-copies [4/4] [UUUU]

md3 : active raid5 sdd4[3] sdb4[1] sdc4[2] sda4[0]
      4370755968 blocks level 5, 128k chunk, algorithm 2 [4/4] [UUUU]

md0 : active raid1 sdd1[3] sdb1[1] sdc1[2] sda1[0]
      200704 blocks [4/4] [UUUU]

unused devices: <none>