Promise Technology FastTRAK66, User Manual

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Understanding Disk Array Concepts
Supported Disk Array T ypes
Striping (RAID 0)
Reads and writes sectors of data
interleaved between multiple drives.
When any disk member fails, it affects
the entire array. Performance is better
than a single drive since the workload
is balanced between the array
members. This array type is for high
performance systems. Identical drives
are recommended for performance as
well as data storage efficiency. The
disk array data capacity is equal to the
number of drive members times the
smallest member capacity. For
example, one 1GB and three 1.2GB
drives will form a 4GB (4 x 1GB) disk
array.
Stripe Size -
a value can be set from
1KB to 1024KB sector size. The size can directly affect performance. In the
FastBuild BIOS, the “Desktop” default is 8KB while “Server” and “A/V Editing”
are 64KB.
Mirroring (RAID 1)
Writes duplicate data on to a pair of drives
while reads are performed in parallel .
IDE RAID 1 is fault tolerant because each
drive of a mirrored pair is installed on
separate connectors - follow the “Drive
Setup By Connector” chart in Chapter 3.
FastTrak66 performs reads using
advanced data handling techniques that
distribute the workload in a more efficient
manner than using a single drive. When
a read request is made, FastTrak66 selects
the drive positioned closest to the
requested data, then looks to the “idle”
drive to perform the next read access.
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