Adaptec MAN-00005-UG, Инструкция по установке и эксплуатации

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© 2003, Adaptec, Inc.
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With Spanning = RAID 30
Benefits: Provides for high transfer rate and high availability, at an inherently lower cost than mirroring.
Drawbacks: Transaction performance is poor because all RAID Level 3 array member disks operate in lockstep.
Drives: Minimum, 3. Maximum, 16.
Fault Tolerance: Yes
B.2.3 RAID 5: Striping with Parity
The controller stripes blocks of data and parity information across all drives.
With Spanning = RAID 50
Benefits: Uses a fraction of the disk space required by RAID 1 to achieve data redundancy. RAID 5 provides
good performance, for transaction processing applications, because each drive can read and write
independently. Should a drive fail, the controller continues to allow reads and writes by calculating
the missing information using the parity data. The controller recreates lost data on a replacement drive
without interrupting access by users. If a hot spare is available, it can perform the rebuild
automatically.
Drawbacks: Cannot match RAID 0 in write performance because of the processing required to compute and write
error-correction data. While a controller is rebuilding a drive, users will experience reduced
performance if they try to read or write data to the array.
Drives: Minimum, 3. Maximum, 16.
Fault Tolerance: Yes
B.2.4 RAID 0+1: Mirroring and Striping
The controller combines the functions of both data striping (RAID 0) and disk mirroring (RAID 1).
With Spanning = RAID 0+1+0
Benefits: Optimizes for both fault tolerance and performance. RAID 0+1 provides excellent performance for all
data needs.
Drawbacks: Requires half the available disk space for data redundancy, the same as RAID level 1.
Drives: Minimum, 3. Maximum, 16.
Fault Tolerance: Yes
B.2.5 JBOD (Just a Bunch of Drives): Single drive control
The controller treats each drive as a stand-alone disk and provides a high-performance cache (sometimes referred to as a
standalone drive).
Benefits: Cache reduces the amount of time the computer waits for a disk to get to the right place to read or
write data.
Drawbacks: Does not provide data redundancy and does not use striping for performance enhancements.
Drives: Minimum, 1. Maximum, 1.
Fault Tolerance: No