Promise Technology FastTrak S150 - Manual (Page 66)

FastTrak S150 TX4 User Manual
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Q: How does the FastTrak S150 TX4 RAID controller provide storage and/or
data protection with their arrays?
A: FastTrak S150 TX4 implements three different types of RAID levels as
follows:
RAID 0 (Stripe)
For capacity – The FastTrak S150 TX4 array will be as big as the smallest HDD
in the array times however many HDDs are in the array. Any larger HDDs will
simply be truncated. The truncated space on the bigger HDDs will then be
unusable.
For sustained data transfers – Using FastTrak S150 TX4, a RAID 0 array
consisting of two HDDs will transfer at about twice the speed of the slowest HDD
in the array. A RAID 0 array consisting of four HDDs will transfer at about three
times the speed of the slowest HDD in the array.
RAID 1 (Mirror)
For capacity – The FastTrak S150 TX4 array will be as big as the smallest HDD
in the array. The larger HDD will simply be truncated. The truncated space on
the bigger HDD will then be unusable.
For sustained data transfers – The FastTrak S150 TX4 array will write data at
the rate of the slowest HDD in the array. The FastTrak S150 TX4 array will read
data at twice the rate of the slowest HDD in the array.
Drive Issues
Q: Can I add a drive to a FastTrak S150 TX4 RAID array via hot-swap and
dynamically adjust the array size/configuration?
A: No. The FastTrak S150 TX4 system does not support dynamically
adjustable RAID size/configurations.
Q: Do the HDDs on the FastTrak S150 TX4 have to be the same size?
A: The HDDs that you use with the FastTrak S150 TX4 do not have to be the
same size. If the sizes differ, the FastTrak S150 TX4 will truncate the bigger
HDD so the drives match. The resulting difference in HDD space is unusable, so
avoid using HDDs of significantly different capacities.
Q: I already have an array on an older FastTrak controller. Can I move that
array to my new FastTrak S150 TX4 controller?
A: Yes. All FastTrak controllers read the arrays the same way and can be
moved from one controller to another.