External hard drive has lost all its data

[Angrboda]

It doesn't seem likely that solid state drives will achieve price parity with spinny disks or flash anytime soon.

I don't know what the cost per GB is, relatively, but the price of SSDs is expected to fall by 50% again this year, so purchasing later rather than sooner, if possible, is recommended. That's the boat I'm in. I have a 256 GB SSD whose "life remaining" before it becomes a door stop has been dropping precipitously the past few months. I moved the pagefile off it, and that may have helped. But eventually, when SSDs have hit a good price point this year, I'll slave two ~250 GB SSDs together in a RAID 0 array. Until then, I'm just biding my time. I may ultimately not, as I've managed to keep things comfortable with only 256 GB. Larger SSDs also means more complicated backup strategies, as there are things that I now keep on my SSD which don't belong being backed up with the operating system. So I back those up to other locations separately. Not a big deal, I suppose, but it means that I have to be vigilant and not let something sitting on the SSD fall between the cracks and not get backed up. The little reading I've done says that SSDs are more likely to fail catastrophically than conventional disks are. If true, because you have some warning with conventional disks, but not with SSDs, a good backup regimen is important with them.

I just finished testing 5 new (used) disks that I'm going to use in a 6 drive RAID 6 array. Two of the three drives in a RAID 5 array were displaying signs of imminent failure, and so this past month or two I've been preparing for recovery of the data on the failing array, and replacement of that technology (doubling the storage space, hardware based RAID 6 instead of software based RAID 5, and an external hard disk backing the RAID 6 array against catastrophic loss). I've been using a smartctl based disk diagnostic and S.M.A.R.T. tool and that from Western Digital themselves. Strangely, the two aren't simply different implementations of the same internal S.M.A.R.T. tests, with the WD tool completing in 4 hours, compared to the smartctl tool taking 5 hours, and the smartctl tool not completing the test on two disks (80%), whereas the WD tool does. It leaves me a little uneasy putting all my confidence in the WD tool, as I don't know what each tool is doing such that there are differences between them. Tentatively, I'm going to go ahead and prepare the disks for production. They all have a one year warranty from the seller in case something reveals itself in production use that didn't reveal itself in static testing.