Promise Technology FastTrak TX4000 - Manual (Page 68)

FastTrak TX4000 User Manual
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Q: How does the FastTrak TX4000 RAID controller provide storage and/or
data protection with their arrays?
A: FastTrak TX4000 implements three different RAID levels as follows:
RAID 0 (Stripe)
For capacity – The FastTrak TX4000 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 TX4000, 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 fault tolerance – The FastTrak TX4000 array will be one-half as big as the
smaller 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 TX4000 array will write data at the
rate of the slowest HDD in the array. The FastTrak TX4000 array will read data
at twice the rate of the slowest HDD in the array.
RAID 0+1 (Mirror)
For capacity and fault tolerance – The FastTrak TX4000 array will be equal to
one-half the number of drives times the capacity of the smallest HDD in the
array. Larger HDDs will be truncated and that space will be unusable.
For sustained data transfers – The FastTrak TX4000 array will read and write
data at twice the rate of the slowest HDD in the array.
Drive Issues
Q: Can I add a drive to a FastTrak TX4000 RAID array via hot-swap and
dynamically adjust the array size/configuration?
A: No. The FastTrak TX4000 system does not support dynamically adjustable
RAID size/configurations.
Q: Do the HDDs on the FastTrak TX4000 have to be the same size?
A: The HDDs that you use with the FastTrak TX4000 do not have to be the
same size. If the sizes differ, the FastTrak TX4000 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 TX4000 controller?