Data Recovery Blog

Data Recovery on a 24 x 2TB disk RAID 6 Storage Array - What A Monster !!!

Have you ever wondered how organisations like the Ordanance Survey and applications like Google Earth get their data ?

Typically, these organisations will commission an aerial photography company to go up in a helicopter and take thousands of very high resolution photos of the area they want surveying. During the photography processes, the images are automatically tagged with GPS and meta data that allows each photo to be joined together to produce an overall photographic representation of the entire area. Using the meta information, these can then be further mapped and overlayed onto satellite images and other types of data.

As you'll probably know if you own a decent digital camera, digital photographs create large files... for example, an 8 megapixel camera will create JPG images of roughly 1.4MB per picture. Aerial photographers will typically use a resolution of 18017 x 45801 - which creates a JPG of roughly 1.03GB in size - this is 1000 times larger than what an 8 megapixel camera produces !! - Now as you can imagine, the storage capacity necessary to hold thousands of these aerial images is immense, a 2TB disk will only hold approx 1600 images of this resolution.

We received an enquiry for data recovery from one such company. They had a storage array consisting of 24 x 2TB SATA HD's containing hi-resolution aerial photographs of various parts of the UK landscape.

The RAID array was in a rack which was located underneath an air conditioning unit. Over a weekend the air conditioning unit developed a leak which spilt cooling fluid into the array taking 7 drives offline and the whole array down.

Once we were able to get data access restored to the drives we were able to work out the RAID configuration - which we found to be a 23 disk RAID 6 using Reed-Solomon error correction with 1 hot spare. This gave us a theoretical storage capacity of 42TB (21 x 2TB). The array was practically full with 41TB of data held on it - approximately 33,000 pictures, all of which we were able to recover successfully.

Data Clinic successfully retrieve critical data for Creative Waterjet Ltd

Established in 2008, Creative Water Jet Ltd is a company based in West Yorkshire that specialise in the computer controlled waterjet machining of virtually any type of material. From plastics and bamboo through to products like laptops and glass to more conventional materials like Aluminium, Brass and Stainless Steel, their processes use an ultra high pressure jet of water which is mixed with sand (abrasive) to create a cutting tool. The water acts as a carrier for the abrasive and it's the abrasive that forms the cutting tool.

Data Clinic received a mid week emergency call from Creative Waterjet informing us that their main system was down and their data (accounts information, invoicing, emails, and machine tooling instructions) was no longer accessible. Their business was therefore at a standstill.

We advised them to send someone across to us with the hard drive so we could take a look and perform an analysis on a while-u-wait basis.

The analysis showed that the drive's microprogramming had become corrupted. This was the reason why the data had become inaccessible, and in order to restore access to the data it was necessary to re-program the drive's ROM with it's pre-failure parameters.

This was successfully actioned and the drive (now with full access to it's data restored) returned back to the customer. Creative Waterjet were then able to reintroduce the drive back into their system and get up and running again immediately.

Data Clinic have two data recovery centres in West Yorkshire -
Data Clinic Leeds, City West Business Park, Gelderd Road, LEEDS LS12 6LN - Leeds Data Recovery Site
Data Clinic Sheffield, 2nd Floor, The Portergate, Ecclesall Road, SHEFFIELD S11 8NX - Sheffield Data Recovery Site

Data Clinic - Main Site

Creative Waterjet Ltd - Main Site

Seagate Momentus 5400.6 laptop hard drives... a worrying trend ????

Article - The Golden Rules for WHAT TO DO when you lose your data

What's the similarity between: Dropping your hard drive on the floor Turning your computer on only to hear your drive making a ticking noise Getting the 'blue screen of death' ? The answer is that all these instances relate in one way or another to DATA LOSS So, here's a very useful article that tells you what you should and what you should not to do if have lost your data... http://ezinearticles.com/?Data-Loss:-The-Golden-Rules-for-What-to-Do-When-You-Lose-Your-Data&id=6585711