Cheadle Data Recovery, like many other data recovery companies, is taking a welcome break over the Christmas period. Doors close here at 5pm on the 23rd of December and do not re-open until 1pm Thursday the 5th of January.
Have a Merry Christmas and a Happy New Year.
In the mean time if have lots of failed disk drives perhaps you could make the following:
Don't make one of these if you require your data back
If system administrators or home users ever thought that their data would be perfectly safe as it was on a RAID/server device please review your setup. In the last 10 days Cheadle Data Recovery has had a significantly increased work load relating to failed RAID and data loss. Including receiving the following:
This server looks as if it is still working.
So far a good recovery has been made on each of these devices, including an emergency 24 to 48 hour service on the 8TB RAID 10. This was exceptionally challenging given the high capacity HDDs and the amount of active data stored on the array. One of the most significant aspects of 4 of the 5 RAID recoveries we have received in was that the system administrators did not attempt rebuild or recover data themselves. We have made a full recovery on each. Unfortunately in the case of the RAID 1 the owner did attempt a rebuild and has written between 10-15GB of new data to the drive, making a full recovery impossible. The rule is, if it is important data don’t risk it and contact us for expert help.
In the past week Cheadle Data Recovery has received two HP/Compaq servers in for recovery. These servers / RAID controllers use a non-standard scheme of striping called delayed parity. Consequently they represent more of a challenge in the recovery environment than other servers. For those system administrators who understand the principles of RAID 5 parity and think they apply to HP/Compaq RAID, then unfortunately the rule book goes out of the window. We advise that if your data is important that you make no attempt at rebuilding the array or reinitialising disks – it could very well lead to data loss.
So, what’s different about the HP/Compaq RAID parameters? Essentially two different block sizes are used. One refers to the parity size and the other for the data. The parity block size is an integral multiple of data block size. In addition to this there are two further parameters that are required for a HP/Compaq RAID configuration – delay and firstdelay. Delay parameter indicates multiplicity, namely how many data blocks fit into one parity block; firstdelay shows how many data blocks are contained in the first parity block.
As you might guess by now, more than just guess work is required to find the correct configuration on a set of hard disks from a HP/Compaq RAID array. If drives are missing, not in their original order, or a bad rebuild has taken place, you require expert knowledge to make a full recovery of the data. If you do find yourself in this situation please contact us. Cheadle Data Recovery has a free call out service to examine failed RAID arrays and servers.
