Running RAID in a Fedora System

[Xose Vazquez Perez]

Hans Müller wrote:

> raid 10 when 1 disk in the raid1 and 1 disk in the raid0 part fail then all 
> data is lost. only one or more disk of the raid 0 OR of the raid 1 part can 
> fail without any data lost. 

You are wrong. raid 10 and 01 are different.

     _____o_____
   __X__     __Y__
   |   |     |   |
  [A] [B]   [C] [D]


RAID 10:
A+B and C+D are two raid 1(X and Y)
the union 'o' is a raid 0.

RAID 01:
A+B and C+D are two raid 0(X and Y)
the union 'o' is a raid 1.

- 10 supports a lost of one disk in every raid_1, can fail:

A and C
A and D
B and C
B and D

- 01 supports a lost of one raid_0 set, can fail:

X, (A and/or B) is the same because the strip is broken
Y, (C and/or D) is the same because the strip is broken