Gillware Inc.

Single level RAID 0 is a RAID configuration without redundancy. If any drive in a RAID 0 array fails, the whole array fails and the system will not be able to read or write files. Data from individual disks can be recovered but it is useless unless it can be reconstructed properly. Since every RAID 0 implementation has unique configuration parameters, RAID 0 reconstruction is a very difficult task. At Gillware, we have technicians that specialize in RAID 0 reconstructions and a wide variety of tools to accomplish to task. We also have the ability to develop custom programs to reconstruct RAID 0 arrays of odd configurations.

Raid 0 reconstruction prices depend on the stripe width of the array (number of drives being striped) and the total capacity of the array. Please call our toll free number 877 624 7206 for a quote.

Raid 0 arrays are built for performance. Instead of reading/writing 1 file to 1 disk, RAID 0 arrays read/write 1 file to multiple disks in parallel. The process of breaking up a file into pieces and writing it to multiple disks is called striping. The following is a simple example illustrating how RAID 0 works.

Say we have a text file that consists of four characters "ABCD" and a RAID 0 array of two disks (stripe width of two) with a stripe/block size of four bits (equal to one half of a character).

Here's a data representation of our text file:

Text in file

Text in file	A		B		C		D
ASCII code	4	1	4	2	4	3	4	4
Raw binary data	0 1 0 0	0 0 0 1	0 1 0 0	0 0 1 0	0 1 0 0	0 0 1 1	0 1 0 0	0 1 0 0

Here's what happens when we save the file:

The first block of four bits (first half of letter A) is written to disk 1 and the second block of four bits (second half of letter A) is written to disk 2. This pattern will repeat until all bits are written.

DISK 1	DISK 2
0 1 0 0	0 0 0 1	A
0 1 0 0	0 0 1 0	B
0 1 0 0	0 0 1 1	C
0 1 0 0	0 1 0 0	D

As you can see, half of the file is on disk 1 and the other half is on disk 2. Notice that the file is not split down the middle (down the middle would have "AB" on disk 1 and "CD" on disk 2). Half of each character is stored on each disk.

Now consider what happens when a disk fails and the data from each disk is recovered.

DISK 1		DISK 2
0 1 0 0 0 1 0 0	D	0 0 0 1 0 0 1 0	"DC2"
0 1 0 0 0 1 0 0	D	0 0 1 1 0 1 0 0	4

Disk 1 by itself contains the text "DD" and disk 2 by itself contains a special character called "Device Control 2" and the number 4. Obviously, the data from each disk is garbage unless it's reconstructed in the proper order.

The array must be reconstructed properly by assembling alternating blocks from disk 1 and disk 2 like this:

0 1 0 0	A
0 0 0 1
0 1 0 0	B
0 0 1 0
0 1 0 0	C
0 0 1 1
0 1 0 0	D
0 1 0 0

Gillware looks forward to helping you with your RAID 0 reconstruction needs. To place an order please call our 800 number.

Continue reading about RAID Arrays at one of our informational pages listed below.