RAID 5 DATA RECOVERY

A RAID-5 volume is a fault-tolerant volume with data and parity striped intermittently across three or more physical disks. RAID 5 stores data on each drive at the same time in the form of blocks called stripes. RAID 5 efficiency goes up as the number of disks increases. If a portion of a physical disk fails, you can recreate the data that was on the failed portion from the remaining data and parity. RAID-5 volumes are a good solution for data redundancy in a computer environment in which most activity consists of reading data.

With no dedicated parity drive the write performance is better, with overlapped data and parity update writes. Read operations can be interleaved as all drives contain data stripes. RAID 1 performs faster but RAID 5 provides better storage efficiency. Parity update can be more efficiently handled by RAID 5, by checking for data bit changes and only changing the corresponding parity bits. For small data writes improvements here are lost as most disk drives update sectors entirely for any write operation. For larger writes only the sectors where bit changes need to be made are rewritten and improvements made. Maintaining parity information reduces write performance ? in some cases as low as one third the speed of RAID 1. For this reason RAID 5 is not normally used in performance critical processes.

RAID 5 provides fair data security and needs three or more disk. If one of the hard fails, the Raid can let the user access the data and will be working but at degraded level. Some Raids will use the hot spare drive by themselves and rebuild the RAID. A hot-spare drive is a hard disk drive in a server that is defined for automatic use in the event of a drive failure. If a drive fails, the system can automatically switch to the hot-spare drive, and the data from the dead drive is reconstructed on the hot-spare drive. The system does not need to be shut down and the controller card will do the rebuilding. In others, user have to shut down the RAID to replace the faulty drive. At degraded level, there is no fault tolerance. User must replace the faulty drive as soon as possible to lesson the chances of data loss. If any of the drives in the degraded RAID had a problem, the data loss is inevitable.

In RAID-5, data is lost when user have problem with more than one disk drives. If you have problem with the RAID 5, check the drives and make sure if they working physically. In most systems, the green light on hard drive containers will let you know, if it is working. You can also see the drive in the BIOS.

If two or more drives have problems, shut down the server. You need professional help. Further working with the RAID may lead to complete loss of data.

Please don't regenerate or rebuild the RAID, if two or more drives have physical problem. This can lead to complete data loss. If you had a problem, give us call for further assistance for RAID 5 data recovery.