Raid Data Recovery

With the cost of the fall of the hard disk, it is not uncommon for desktop PCs for the home have RAID. In fact, most PC motherboards have a built-in RAID controller, even when not in use. RAID is the abbreviation for “Redundant Array of Inexpensive Disks” and was developed for use in small disks of an array for better performance, scalability and data reliability and recovery.

RAID achieves all these goals through various configurations. The most common nowadays are RAID 0, RAID 1, RAID 0 +1 / RAID 5 and RAID 10. Each of these RAID types has its own method of redundancy.

RAID 0 is simply the striping of data across multiple disks. It’s like splitting the data into smaller pieces of fixed size, called “bandwidth” and rays through writing disks. If the file was being written 5KB in size, with a bandwidth of 1 KB and there are 4 disks in a RAID set, the first band that is written in the first disc, the second in the second disk, and so on until Banda the fourth, the fifth band is written in the first disc. This is a quick way to write large files but if one disk fails, all fails.

RAID 1 is also called mirroring. That’s because the same data is written to two disks simultaneously. In other words, a disk in a mirror image of another. The readings are done in both units as well. If one disk fails, there is another record that still keeps the data safe and read and write operations continue. This is a cost-effective to have two discs to do a job.

RAID 0 + 1, is a combination of RAID 0 and RAID 1. Data is striped on the disks, and then reflected through the same number of disks. If you have four disks, data is striped in the first two, and then the couple is reflected in the other two discs. This is a solid solution, but very expensive.

RAID 5 is like RAID 0, but with a parity write. A parity is an error correction which is a combination of data on other bands. Furthermore, parity is written on different disks, and not on a single disc. Due to this overload, RAID 5 is slower than RAID 1 or RAID 0 + 1.

In the case of a disk failure, data can be retrieved by calculating the contents of the parity disk from the contents of the other discs. In installations of hot swapping, the disc is removed and replaced, and the data is rebuilt on the fly. Would have significant performance degradation while the data are retrieved automatically.

RAID has been designed to be scalable and robust. But with each hard disk the chances of a hard drive failure increases. RAID is also designed to continue operating even if a single disk failure. And depending on the RAID 0 +1 configuration, although more data disks are not yet written and read correctly to a certain extent, but with significant performance degradation.

However, in most cases, it would still be necessary to make a RAID recovery sometime in the multiple disk failures. RAID data recovery is specialized for different types of disks and RAID implementation strategy. RAID data recovery is necessary in some cases a laboratory for the study of clean room to retrieve the disc before the lack of data.

Most data centers use the redundancy of the additional data storage and retrieval of data from the RAID configuration has been fixed. In other cases, data are retrieved from tape backup after repair the RAID. In the worst case, important data, RAID data recovery is done by companies that specialize in the treatment of RAID configurations daily.