RAID and Subsystem Architectures RAID Configurations
Comparing RAID 0+1 and 1+0
=
RAID 0 + 1
Block C1 Block B3 Block B1
Block A5 Block A3 Block A1
Block C2 Block B4 Block B2
Block A6 Block A4 Block A2
Reverts to an unprotected RAID 0 if there is a single disk failure in any stripe. Cannot recover from a failure in both stripes
RAI ==
D 1 + 0
Block C1 Block B3 Block B1
Block A5 Block A3 Block A1
=
Block C1 Block B3 Block B1
Block C2 Block B4 Block B2
=
Block A5 Block A3 Block A1
Block A6 Block A4 Block A2
X X X
Block C1 Block B3 Block B1
Block A5 Block A3 Block A1
Block C2 Block B4 Block B2
Block A6 Block A4 Block A2
Block C2 Block B4 Block B2
Block A6 Block A4 Block A2
Can recover from a disk failure in either stripe. If there is a disk failure in both stripes on the same mirror, then data is lost.
RAID 0 + 1 (Striped mirroring array): If we lose a disk in one of the stripes, then all the data is lost in that stripe and the volume reverts back to an unprotected RAID 0 If we lose a second disk anywhere in the other stripe then all data is lost.
RAID 1 + 0 (Mirrored striping array): If we lose a disk in one of the stripes, then the data can be recovered from the mirrored disk. If another disk fails, then data can still be recovered from the mirror. If both disks in the same mirror fail, then all data is lost.