Data Volume lost after disk replacement on Readynas Pro 6

Succes! The data is back!

Most discussions I recently read on raid 5 recovery were not very encouraging. And XRaid-2 got even less reactions, let alone positive ones. Not very promising: After I had made the images of the six drives I tried first to repair the faulty disk that started the disaster.  Not immediately succesfull I turned  to software recovery from the images. I started with Reclaime's free raid recovery, but that did not work for me.The raid array was not recognised. During the scans I searched for the raid parameters of a XRaid-2 config. Turns out they do not exist, as it is a dynamic raid setup. Then I found a first digestable insight in nas partitions, with referral to readynas XRaid-2 on Youtube: https://youtu.be/kGvBZdKFdFc. After 20 minutes on btrfs, lvm and dynamic raid arrays, recovering dynamic raid arrays did not sound very promising anymore..

I tried RTT's software, and I contacted a few software vendors, who let me know that as XRaid-2 is a proprietary raid setup they could not detect, analyse or repair it. Encouragement levels dropping ...

I then contacted Reclaime with the question if their "free raid recovery" software could (should be able to) detect and rebuild the XRaid-2 array from a six disk array with one probably missing (the failed sync on disk 2). I got a message back advising me to use "Reclaime File Recovery". This did not immediately work, but it did provide some encouraging results recognising the size of the array and the original number of drives. After a few mails and an update the software recognised all the images and the full original array. Within minutes the original filesystem was available after which I started copying out files to my JBOD NV+. Within three hours I had recoverd all my critical data.

At the moment I am still copying less important files, but I am not entirely sure if I will recover all the data. It might be that I have lost something due to the two drive crashes and subsequent sync and scrub actions. The software is still analysing the disc-images, repiecing files that might have been unreadable due to the disk crashes or deleted due to the failed sync process or disk scrub. I understand that btrfs is good for that, lets see.

Me however, I am amazed, and as you may image very, very happy that I found a solution. One of the things that impressed me is Reclaime's software, their knowledge or raid arrays, HDD drives and Nas system,  and their support: Exemplary. Turns out that the video I found was theirs, and they have a whole library of youtube video's on the subjects, higly recommended.

So, what's next: setup my readynas pro again as a X-Raid2 system? Well.. with solutions from Recliame I might just give it a go again....

But I probaly won't: If I am correct the key reason for Raid was to offer multiple fysical drives as one logical volume, thus offering capacity and speed.  (in 1995, a 1GB HDD became commonplace according to http://www.relativelyinteresting.com/comparing-todays-computers-to-1995s/)  This introduced interdependency between disks that was subsequently adressed with parity or redundancy, or both.

Today's 2TB HDD's are common, fast, and can store so much data that I really wonder if there is a need to offer multiple 2GB drives in a raid/parity setup as one logical drive for a home situation, or a small office. And as we still need to rely on a backups I believe there is a good case for increasing capacity eliminating parity, and reducing dependency between disks, thus avoiding Raid completely: A weekly backup may do, and I will never lose more than the actual disks that fail, if the backup fails too. Much less risk, and what is more, much less hassle, especially in recovery...