Klennet Storage Software

Pricing and freebies in data recovery

I came across this Reddit Post today, which starts with a definition of the problem

... a bit of mess transitioning a storage pool from Server 2012 to Windows 10... now it seems I've reset all three disks and there is no longer a pool. ... The three 4TB drives were configured in a parity with just under 8TB usable.

So, we’re talking about 3x 4TB Storage Spaces pool which has its metadata damaged to the point the pool is no longer recognized. There is an obvious solution:

  1. Get some data recovery software which is capable of reading the pool;
  2. try its evaluation version (most all software has some kind of evaluation allowing you to see what can be recovered; at least every first-tier software has);
  3. if the result is satisfactory, buy a license and copy data away.

In practice, you can’t get it any simpler. Can you get it any cheaper though?

Now ReclaiMe can see the partition and show me almost all of the files. Do any of you lovely folks know a way I can try to reinstate the pool without losing the 6TB of data that was on those drives? Preferably without forking out for ReclaiMe and buying drives to transfer the data to.

That bit of ReclaiMe seeing the partition confirms that the data is there in some form, but the "almost all" part of it suggests there may be some damage not limited to the pool metadata. This would make things infinitely more complicated if it happens to be true. But, let’s consider just for the sake of the discussion that it is the pool that is kaput, not the filesystem inside the pool.

There is no reliable way to reinstate the pool if it is already unrecognizable. Nobody knows exactly how the damn thing goes through all its different failure modes, there are several different versions, and if something happened during transition, well, it is now some mixed version of the pool which in all likelihood nobody had ever seen before.

As far as costs go, development costs required against something like Storage Spaces just to understand it good enough to be able to recover data from it are typically upwards of $100K (mostly in developer time, hardware is relatively cheap). Reverse engineering of a filesystem or a lower-level storage system like Storage Spaces takes something like six month to a year of work to produce results usable in data recovery. And I'm thinking people with several years of experience in a pretty specific area of reverse-engineering storage systems.

Therefore, it is not likely you can get a free usable manual on what to do with a failed pool. People who spent a year on it are not likely to put it out for free. Not that it is impossible, it is just not likely. Far worse, it is unlikely that any usable manual can be produced at all. Something consisting of ten thousand steps is not considered usable, and that may well be the minimum number of steps required to fix the failed pool. In practice, the cheapest option would be to shell out some money for (in this particular case) ReclaiMe license, or just forget about the data and re-create the pool. This would be cheapest in terms of money and time invested. Additional spending would be a purchase of 2x 4TB drives to store the recovered data. However, the drives can be put to good use to hold a backup of the data, once the data is recovered.

For a reasonably complex data recovery problem, be it hardware or software, you are not going to find any free solution. The development costs are too big for that. For a hardware problem, there is typically some added cost in donor parts, and even in software-only recoveries there is a cost of whatever additional storage may be required.

Free data recovery software

...but wait! There are some free data recovery products?!

Sure, there are. Let’s see examples,

  • ZAR, obviously. ZAR free image recovery part falls into a "reasonably simple" category. Similar to it would be PhotoRec by CgSecurity.
  • TestDisk (again by CgSecurity) which is a command-line tool of reasonably good capability to rebuild partition tables, and some capability to deal with a damaged filesystem. This is also "reasonably simple", and it is, like, command line.
  • Recuva by Piriform, which is actually either paid or ad-sponsored (as of February 2018), not a freeware.

So, what are the options?

If the case is possible to fix in software, the best option is most likely to use the software. Simple cases can be handled with free software, more complicated cases with paid software. Looking for some trick to make a system work again is usually not productive.

If the case involves a hardware problem, there are no working DIY solutions other than connecting external drives to a motherboard SATA port to see if it works without any USB involved. Hardware problems are for the labs.

Created Saturday, March 3, 2018

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