RAID 6 distributes data across several disks while protecting the data against a
two disk failures or a single disk failure and read error in another disk. This
protection is achieved by two independent parity algorithms. Data is divided into
blocks, and each block is stored on a different drive. Parity blocks are stored
on two drives and distributed among the disks. RAID 6 efficiently trades off the
capacity of the disks with high fault tolerance, reducing the capacity by two disks.
Storage performance increases with higher read and write transaction rates if a
designated ASIC is used for Reed-Solomon parity computation.
In case of a single disk failure, the array can be work in degraded mode and still
offer some sort of protection againt failure, but not for long. It is advised to
replace the damaged disk as soon as possible to prevent the chance of further failures.
RAID 6 can sustain multiple bad block failures while operating in non-degraded mode
and can sustain a single bad block if degraded. RAID 6 may be rebuilt when a single
disk fails, but the rebuild process will usually fail if more than one disk has
failed, and all the data becomes inaccessible.
RAID 6 Online Recovery Service
Raid Recovery Online (RRO) provides professional online data and RAID recovery services from RAID 6 based systems.
Services are provided online, over a secured channel on the Internet. For a detailed
description of the recovery process, please see the Online
RAID Recovery process.
Online RAID 6 Recovery Service fees are usually fixed in advance, as a function
of the number of disks in the array. However, additional charges may be incurred
for the recovery of heavily damaged files in cases of severe file system damage.
| Number of drives | Price (in $) |
| 4 drives | 5,550 |
| 5 drives | 6,850 |
| 6 or 7 drives | 8,500 |
| 8 drives or more | 14,500 |
Next step -
Free Online Diagnostic