On February 1st, 2018
Here at R3 Data Recovery Hospital, we see all sorts of storage devices from USB Sticks, to hard drives, to servers, RAID arrays and they all come with their unique problems.
Recently we received a 2 disk RAID device, the RAID contained 2 x ST31000528AS 1TB Seagate drives.
After the job was initially booked in and all serial numbers taken note of, the diagnosis stage was begun.
After the engineers had diagnosed both drives they noticed one was making a clicking noise, this would normally point to a mechanical failure which would make sense as to why the RAID failed. After inspecting the drive in our clean room, the engineers noticed it was full of "dust" this is caused by the drives heads failing and scratching along the platter service causing more and more damage the longer the drive is powered on.
In an ideal situation if the drive was powered off as soon as the clicking noise started the drive may not have turned out this way.
This could have been a problem for our engineers as this disk was part of a 2 disk RAID, however at the same time it may also not be. If the RAID was set up as RAID 0 then this is where the problems would begin.
For Example, with a RAID 0 the data is spread across both drives. So, the maximum capacity you can have is both drives included in the RAID added together, so in this case it would have been 2TB’s. However, with a RAID 0 if one drive is in as bad as condition as this one was the RAID wouldn’t be recoverable as you need both drives to recover the data lost.
However, if the RAID was set up as a RAID 1 then the engineers only need 1 disk to recover from the RAID as a RAID 1 is mirrored so the data is the same on both drives. So the maximum capacity you can get is the capacity of one drive so in this case 1TB.
Luckily this customer had the RAID set up as a RAID 1 so even though one drive was unrecoverable the other drive wasn’t, and it was possible a complete image could be made and therefore a full recovery was accomplished. Resulting in a happy Customer and a happy R3 Data Recovery team 🙂