Table of Contents
Advertisement
RAID 60
RAID 60 uses distributed parity, with two independent parity blocks per stripe in each
RAID set, and disk striping. A RAID 60 virtual disk can survive the loss of two disks in
each of the RAID 6 sets without losing data. It works best with data that requires high
reliability, high request rates, high data transfers, and medium-to-large capacity.
RAID 60 provides the features of both RAID 0 and RAID 6 and includes both parity and
disk striping across multiple arrays. RAID 6 supports two independent parity blocks per
stripe. RAID 60 is best implemented on two RAID 6 disk arrays with data striped across
both disk arrays.
RAID 60 divides data into smaller blocks, then stripes the blocks of data to each RAID 6
disk set. RAID 6 divides the data into smaller blocks, calculates parity by performing an
Exclusive-Or (XOR) on the blocks, then writes the blocks of data and parity to each drive
in the array. The size of each block is determined by the stripe size parameter, which is
set during the creation of the RAID set.
RAID 60 can support up to 8 spans and tolerate up to 16 drive failures, though less than
total disk drive capacity is available.
Point
Description
uses
Provides a high-level of data protection through the use of a second parity block in each stripe.
Use RAID 60 for data that requires a very high-level of protection from loss.
In the case of a failure of one drive or two drives in a RAID set in a virtual disk, the RAID
controller uses the parity blocks to recreate all the missing information. If two drives in a RAID
6 set in a RAID 60 virtual disk fail, two drive rebuilds are required, one for each drive. These
rebuilds do not occur at the same time. The controller rebuilds one failed drive, and then the
other failed drive.
Use for office automation and online customer service that requires fault tolerance. Use for any
application that has high read request rates but low write request rates.
strong points
Provides data redundancy, high read rates, and good performance in most environments. Each
RAID 6 set can survive the loss of two drives or the loss of a drive while another drive is being
rebuilt. Provides the highest level of protection against drive failures of all of the RAID levels.
Read performance is similar to that of RAID 50, though random reads in RAID 60 might be
slightly faster because data is spread across at least one more disk in each RAID 6 set.
weak points
Not well suited to tasks requiring lot of writes. A RAID 60 virtual disk has to generate two sets
of parity data for each write operation, which results in a significant decrease in performance
during writes. Disk drive performance is reduced during a drive rebuild. Environments with few
processes do not perform as well because the RAID overhead is not offset by the performance
gains in handling simultaneous processes. RAID 6 costs more because of the extra capacity
required by using two parity blocks per stripe.
hard disk drives
A minimum of eight hard disk drives.
Appendix A : RAID 165
Advertisement
Table of Contents
