Raid Nas Data Recovery
Dedicated Raid systemsare typically found in servers and are implemented by using a dedicated RAID controller card or the in-built functionality contained on modern server motherboards and allow for data to span multiple drives as can be seen with image right
NAS systemsare typically used as backup systems for smaller enterprises and the RAID is implemented in software via the Linux operating system which is slower that dedicated RAID controllers. It should be noted that NAS raid devices should be used as a backup device and not as a primary storage option.
RAID 0 - is based on a striping technique which does not provide redundancy ( duplication) and it is used mainly to increase system performance because N-disks array provides N times read and write speed improvement as compared to a single disk. RAID 0 recovery is relatively simple however if one of the disks is unreadable data recovery is comprimised.
RAID 1 is based on a mirroring technique to enable redundancy and is easy to recover .
RAID 0+1, same as RAID 1+0 is based on mirroring and striping techniques. The array inherits RAID 1 fault tolerance and RAID 0 speed efficiency. There is a 100% disk space overhead in RAID 0+1 implementations. Such arrays will survive a single disk failure and can survive multiple disk failures .
RAID 5 - sometimes called stripe set with parity - utilizes striping and parity techniques. Parity technique provides fault tolerance - in case of a single disk failure the missing data is reconstructed using parity data and data from other member disks. RAID 5 recovery is more complicated than for RAID 0, but the data can still be recovered if one of the disks had failed.
RAID 6 is similar to RAID 5 but utilizes two different parity functions. Usually one of them is the same as in RAID 5 (XOR), but the second is more complex. On the one hand, using the two parity functions enables RAID 6 to survive a dual hard drive failure, on the other hand, the need to store parity data of the two functions results in that the disk space overhead equals the capacity of two member disks. RAID 6 recovery is very complex.
We use a variety of software tools to recover data from damaged RAID's.
- DiskInternals - DiskInternals Raid Recovery
- Runtime - Runtime RAID Reconstructor
- ReclaiMe RAID - ReclaiMe Free RAID Recovery build 301
- R-Studio - R-Studio
- ZAR - Zero Assumption Recovery version 8.5