Let us consider software RAID array recovery.
Main method of data recovery from a RAID array (RAID array recovery) is a data volume rebuild, i.e. by means of a software blocks from different hard drives are being arranged in the correct sequence. The order of the blocks in the array depends on the hard drives locations in the RAID and from the algorithm of the controller itself.
Before starting the RAID array recovery, it is necessary to create clones of the drives in order to protect the original drives from wrong actions. Copies can be made as image files or sector-by-sector images directly on the target drives.
To work with copies or originals is up to you. I highly recommend using the copies since if the original media have bad sectors work with such drives can significantly worsen their condition or lead to a complete failure.
Let’s get started.
To assemble the array, you need to know the parameters it was created with – the block size and sequence of discs.
If they are known it is possible to assume that half of the work has already been done, and we have saved a lot of time for other, more pleasant things. If not, you will have to pick them up.
Fortunately, there are automatic tools for configuration search and the RAID recovery, for example such as RAID Re-constructor software. If you set it in the array level, then it will try to find the original sequence of disks, the block size and assume the information recording algorithm drives.
The first step needed to get started is an array type selection. It performed in the drop-down list «RAID TYPE».
By specifying the type of array to be rebuilt, you must specify the number of drives in the window «#drives». After you do this, the following are highlighted white are several fields (their number will be equal to the number of the discs comprising the RAID). Once the drives are selected – go to next step «Block size».
Here you must specify the block size, if known, if not, leave this option unchanged and click on «Open drives» and then on the button «Analyze».
When the array is assembled correctly, and file systems on it does not have a logical damage, you can get access to the data by standard methods.
The method described above can be restored RAID only in the simplest cases. Description of complex situations beyond the scope of this article, and requires specific knowledge.