Data Recovery Lab
RAID recovery requires patience
We repair then image each drive first. Our experts rebuilt the RAID Array from those images, keeping the original media as it was.
Class 100 clean room
Each hard drive is opened in a dust free environment
We provide extensive RAID recovery services. The safe and proper way is to image all the drives of the RAID array first, then work on those images to rebuilt the data. We often need to repair one or more drives from electronic or mechanical failure first then image afterwards.
In theory, we should not have to perform raid 5 data recovery, since this type of RAID can work in degraded mode until you replace the bad drive, then everything is back to normal once the RAID 5 rebuilds itself.
The most common mistake with RAID 5 is when a good disk is replaced instead of the bad one. An immediate failure occurs since most RAID systems can’t work with 2 disks that are faulty. The same problem occurs if the user specifies a wrong number of disks while rebulding the failed RAID. This often happens due to the use of a hot spare which is not, in theory part of the raid itself.
On the other hand, RAID 0 recovery is common, since this type of RAID offers no tolerance to failure. If any of the drive crash or fail, then your data is gone. We perform a lot of raid recovery on RAID 0.
There is only one case where we can’t recover data. If a RAID is reinitiliazed (which takes hours), all data will be lost. It will basically write 0 over the entire disks. There will be no data left to be recovered.
Corrupted RAID: The symptoms
– Each hard drive appears as unformatted or uninitialised
– MBR Error
– Invalid operating system
– A disk error occurred
– Invalid partition table
Reasons why a RAID fail
There are quite a few reasons. Among them you have the following:
Damaged files, virus attack, corruption of data, bad sector, overwritten files and missing partitions.
Common mistakes on RAID
– Errors made while repairing a degraded RAID
This is one of the most common mistake. Most RAID continue to work in degraded mode after one hard drive fails.The bad disk is supposed to be replaced then the RAID will rebuilt itself and everything should be back to normal.
Here is what usually goes wrong:
A good disk is replaced instead of the bad one. An immediate failure occurs since most RAID can’t work with 2 disks basically not working. It is possible to recover the data using a software like file scavenger.
The user specify a wrong number of disk while rebulding the failed RAID. This happens often due to the use of a hot spare which is not in theory part of the raid itself. Data becomes corrupted and might be lost permanently.
– RAID initialization being performed
If a RAID is reinitiliazed (takes hours) all data will be lost. It will basically write 0 over the entire disks. There will be no data left to be recovered.
– Chkdsk being run on one of the disks
Chkdsk doesn’t know RAID and in general it must be avoided. Most of time the RAID data patterns will be lost and data might be gone permanently.
– A RAID mistakenly configured as another RAID type
– A RAID 0 misconfigured as a RAID 5 or the opposite.
What is RAID?
Raid stands for Redundant Array of Inexpensive Disks. Amongs famous RAID you will find the following.
– RAID 0: Which is a non redundant type of array but provides high performances in terms of writing and reading.
– RAID 1: Also called mirroring without parity or striping. The data are written identically to several hard drives.
– RAID 5: This RAID distributes parity along with the data. It can’t be destroyed by a single drive failure.
– RAID 6: This RAID allows 2 drives to fail.
– RAID 10
– RAID 51
– RAID DP
– And so on
– Maximum number of drives for a raid array
For a maximum safety it is better to use a raid disk array with less than 14 hard drives. If there are too many disk failures, the array rebuilding process will become too slow. An array with less than 14 disks is less complex.
– Here is a non-exhaustive list of RAID Array we work on
RAID 0, 1, 2, 3, 4, 5, 6, 10, NRAID|RAIDn|RAID DP|RAID 01|RAID 0+1|RAID 1+0|RAID 05|RAID 15|RAID 50|RAID 51|RAID 5E|RAID 5EE|RAID 5DP|RAID TP|RAID 1.5|RAID 7| RAID ADG|RAID S|Matrix RAID|IBM ServerRAID 1E|Sun RAID-Z|Netgear X-RAID