Adaptec 2110S - SCSI RAID Controller, User Manual, Page: 138 / 158

B-8
Adaptec Storage Manager Pro User’s Guide
Understanding the Array Selection Criteria
To help you choose an array type, use the criteria in the following
table. Decide how important each criterion is to meeting your data
management and storage needs.
Criteria Definition Examples
Random-read
performance Ability to locate and read
data directly from a file
without having to search
sequentially from the
beginning of the file. Databases, transaction
processing programs,
and operating system
page file
Random-write
performance Ability to write data directly
to a file without having to
search sequentially from the
beginning of the file. Databases, transaction
processing programs,
and operating system
page file
Sequential-
read
performance Ability to read large numbers
of consecutive data elements. Streaming video
programs and backup/
restore programs
Sequential-
write
performance Ability to write large
numbers of consecutive data
elements. Streaming video
programs and backup/
restore programs
Fault
tolerance Ability to recover from a
failure of one or more drives
without interrupting user or
application access to data. Whenever data is more
important than the cost
of storing it
Expansion Ability of the system to
increase the available storage
capacity for the operating
system’s file system. Most systems require
expansion capabilities
to meet growing data
storage needs.
Load
balancing Ability to spread I/O across
drives. All I/O-intensive
applications benefit
from load balancing.
Cost per
usable unit of
space Ability to use all space in an
array to store user data.
(Unusable space includes
parity in a RAID 5 set and the
redundant half of a mirror
set.) N/A