Adaptec DuraStor 7220SS User Manual page 114

Applications Suitable for Mirror Sets
Mirror sets are particularly suitable for the following types of
applications:
Data for which reliability and availability requirements are the
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first priority
Backing up of online data with minimum application downtime
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RAID 5
The RAID 5 set uses parity to provide redundancy. RAID 5 disk
drives may operate independently of each other allowing multiple
simultaneous read and write operations. Parity is distributed
across all the disk drives in the array rather than residing on a
single drive.
A RAID 5 set is made up of at least three equal-sized partitions on
different disk drives. The data is striped evenly across its
respective disk drives in equal-sized chunks , with one chunk of each
stripe used for parity data
the data if one drive fails.
Figure A-6 represents a RAID 5 set made up of four partitions, each
on different disk drives. The free space of the larger drive is not
used.
. This permits the storage system to rebuild
Storage Concepts
A-11