Raid 6 - Inspur 3008 Series Configuration Manual

evenly distributed to all drives in the array by certain rules instead of being written
to a fixed drive. Therefore, each drive contains both data information and parity
information. If any drive fails, data on the failed drive can be rebuilt from the parity
bit data on other drives in the array. RAID 5 requires at least 3 drives. The
advantages are better utilization of the capacity of all redundant drives configured
in the array and excellent read/write performance. Note that drive failures will
affect the throughput rate. This means a longer time is required to rebuild data
than it takes in RAID 1 configuration.
Figure 1-3 RAID 5

1.2.4 RAID 6

Compared with RAID 5, RAID 6 adds a second independent parity block for double
parity. The two independent parity systems use different algorithms to ensure high
data reliability. Data processing is not affected even if 2 drives fail at the same time.
However, RAID 6 requires larger drive space for storing parity information and has
a higher "write penalty" compared with RAID 5. Therefore, RAID 6 provides lower
write performance than RAID 5.
Figure 1-4 RAID 6
3