Adaptec 2130SLP User Guide - Page 166

RAID 1 Logical Drives

Page 166 highlights

Appendix D: Understanding RAID ● 165 RAID 1 Logical Drives A RAID 1 logical drive is built from two disk drives, where one disk drive is a mirror of the other (the same data is stored on each disk drive). Compared to independent disk drives, RAID 1 logical drives provide improved performance, with twice the read rate and an equal write rate of single disks. However, capacity is only 50 percent of independent disk drives. If the RAID 1 logical drive is built from different- sized disk drives, the free space, drive segment size is the size of the smaller disk drive, as shown below. Disk Drive 1 250 GB Drive Segment Size (Smaller Disk Drive) Disk Drive 1 1 - 250 Disk Drive 2 400 GB Disk Drives in Logical Drive Disk Drive 2 1 - 250 Not Used Unused Space: 150 GB RAID 1 Logical Drive = 250 GB

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Appendix D: Understanding RAID
165
RAID 1 Logical Drives
A RAID 1 logical drive is built from two disk drives, where one disk
drive is a
mirror
of the other (the same data is stored on each disk
drive). Compared to independent disk drives, RAID 1 logical drives
provide improved performance, with twice the read rate and an equal
write rate of single disks. However, capacity is only 50 percent of
independent disk drives.
If the RAID 1 logical drive is built from different- sized disk drives, the
free space, drive segment size is the size of the smaller disk drive, as
shown below.
Disk Drive 1
Disk Drive 2
250 GB
400 GB
Disk Drives in Logical Drive
Disk Drive 1
Disk Drive 2
RAID 1 Logical Drive = 250 GB
Not Used
Unused Space: 150 GB
1 – 250
1 – 250
Drive Segment Size (Smaller Disk Drive)