Supero SUPER 370DDE, User Manual

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UPER 370DDE/370SDA User's Manual
Troubleshooting
Striping/Mirror (RAID 0+1)
A combination of both above array types. It can increase performance
by reading and writing data in parallel while protecting data with dupli-
cation. A minimum of four drives needs to be installed. With a four-
drive disk array, two pairs of drives are striped. Each pair mirrors the
data on the other pair of striped drives. The data capacity is similar to a
standard Mirroring array with half of total capacity dedicated for redun-
dancy.
About Dual Data Redundancy
One unique (though rarely occurring) feature of RAID 0+1 is dual fault
tolerance. In some cases, two drives can fail simultaneously and still
maintain the integrity of data. There are six combinations in which two
drives can fail. FastTrak100 protects the data array in four of those
cases depending on drive type (some drives do not permit the Slave
drive to continue to function if the Master drive fails).
Assume the drives are configured as follows (M = Master, A/B indi-
cates which striped pair the drive belongs to, # indicates which part of
stripe data):
IDE 1 IDE2
M Drive A1 Drive B1
S Drive B2 Drive A2