Adaptec SAS/SATA/SCSI RAID Controllers - Manual (Page 72)

Appendix B: Understanding RAID ●
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RAID 10 Arrays
A RAID 10 array is built from two or more equal-sized RAID 1 arrays. Data in a RAID 10 array
is both striped and mirrored. Mirroring provides data protection, and striping improves
performance.
Drive segment size is limited to the size of the smallest disk drive in the array. For instance, an
array with two 250 GB disk drives and two 400 GB disk drives can create two mirrored drive
segments of 250 GB, for a total of 500 GB for the array, as shown in this figure.
Disk Drive 1
Disk Drive 2
Disk Drive 3
Disk Drive 4
250 GB
250 GB
400 GB
400 GB
Drive Segment Size
(Smallest Disk Drive)
Disk Drive 2
Disk Drive 3
Disk Drive 4
Disk Drive 1
1 3 ... 499
2 4 ... 500
1 3 ... 499
2 4 ... 500
Unused Space = 150 GB
Disk Drives in Logical Drive RAID 10 Logical Drive = 500 GB
Unused Space = 150 GB