Raid 5 information

This level of raid 5 has data as well as parity striped over all the disks. It is almost like the raid level 4 only with the exception of dedicated parity in the raid level 4. As the data is being striped over another disk in raid level 5, it has more capacity.

To set up raid 5 effectively, on requires 3 disks (minimum) while the maximum can be as many as 32. All the disks should be similar in type and size.

Its random read performance is quite good. This is mainly because the data and parity is striped over all the disks and during normal read operation, no parity information is required. Random write performance is not great because of parity overhead. Sequential read and write performance are fairly good.

Raid 5 can tolerate the loss of a single disk. But what if simultaneously two disk fails before raid 5 recovery and rebuild process is completed? At such a situation, raid 5 data recovery is required.

Raid 5 failure can be broadly divided into physical array and logical array failure. In case of physical array failure one or two hard disks fails whereas in logical array failure, a partition might get corrupted. In both cases if raid recovery is not performed, there could be a serious loss of data.

Recovering raid 5 data involves using recovery software if the failure is of the logical type. For physical disk failures, after the data has been extracted the corrupted disks are replaced by new ones. There are raid data recovery labs where the disks could be sent for recovery. It is advisable to not try raid recovery at home, if you are not a professional.

RAID level 5 is just the right combination of great performance with good capacity and performance. It can be used where a high read operation as well as storage is required. In relational database type applications, Raid level 5 would be efficient.

Raid 5 has many advantages. It is comparatively cheap and its data availability is good. It also supports high fault tolerance. Moreover, parity information is stored in a very small space i.e. equal to 1/ number of disks.

Raid level 5 suffers from a certain disadvantages. Its write performance is just not good. It has high-end controller requirement. Moreover, with the increased number of disks in an array, the complexity increases. Even though it suffers from these disadvantages, it is still the most popular raid level and is highly used.