• Data Recovery
• Hard Disk Drives (HDD)
• Desktop Computers
• Laptop Computers
• Server Systems
• Apple Mac Systems
• RAID Based Systems
• Tape Data Recovery
• Digital Memory Media
• Memory Cards, USB Memory Sticks
• Advanced Memory Recovery Techniques
• Free Photo Recovery Software
• Optical Media (CDs, DVDs)
• Other Magnetic Media
• Data Recovery Technology
• Data Recovery News
• Quotes
• Specialist Services
• Site Map
• Articles on Data Recovery
• Data Recovery Software

RAID data recovery specialists - Tel: 0800 072 3282

Because of multi-drive configurations data recovery from RAID arrays is a complex process requiring skilled engineers. We are able to work out stripe rotation, block sizes and parity without needing the RAID controller card. This helps speed up the data recovery process as you can prepare a new RAID system and copy the recovered data to that.

Because of our in-depth knowledge of how RAID systems and Volume Sets work we often recover data where many others have failed, particularly with Compaq and HP RAID arrays. We always offer free diagnosis, realistic prices and will not charge you if your data is not recoverable.

Usually, we can provide a same or next day data recovery service to get you back in business as quickly as possible.

What is RAID?

Redundant Array of Inexpensive Drives (RAID) is a method of increasing data storage by means of using groups or 'arrays' of small (inexpensive) hard drives creating a single large volume. There are several RAID array configurations and each has its advantages and disadvantages.

• RAID 0 (Striping Without Parity) consists of two or more disk drives with the data striped across the entire array. There is no fault tolerance, so a failure within a RAID 0 array will result in inaccessible data.
• RAID 1 (Mirroring and Duplexing) - Consists of at least two disk drives. The data on the second drive is identical to the data on the first drive. If one disk drive fails, then there is a complete copy on the other drive.
• RAID 2 (Hamming). Rarely used these days but was fairly common before ECC (error correction codes) became built in on IDE hard disks.
• RAID 3 (Striping with Parity). Needs at least three disk drives. Data is striped across two drives with the third drive holding parity information. If any one disk drive fails, then the data can be rebuilt using the other two. Data is striped at byte levels usually under 1024 bytes per stripe. Arrays with dedicated parity drives found in RAID 3 and 4 can be sluggish when writing as there is a bottleneck on writes to the parity drive.
• RAID 4 (Striping With Parity) Similar to RAID 3 but data is striped in blocks, typically 64k but can be other sizes.
• RAID 5 is the most common RAID level and requires at least three disk drives. Data is stored in stripes with a distributed parity stripe across the drives. This removes the bottleneck found in RAID 3 and 4 and is the best option when considering RAID arrays with parity.
• RAID 6 (Block-level striping with dual distributed parity). Similar to RAID 5 but there are two distributed parity stripes, this configuration has lower performance than RAID 5 but offers greater fault tolerance as two drives in the array can fail without loss of data.

There are also several 'hybrid' RAID levels, such as RAID 10 (OR RAID 1+0) this is where two separate arrays are combined into a single volume. For example ...

• RAID 10 There may be 4 disk drives in the array, two are RAID 0, and the other two are also RAID 0 but mirror the first pair.
• RAID 51 you may have 6 disk drives in the array, configured as two x 3-drive RAID5 volumes. The second set mirroring the first set. In theory this gives better redundancy that standard RAID5 as up to 3 drives can fail before data is lost.

When using any type of RAID array based storage system, all drives in the array are presented to the operating system as a single volume.