The system is currently working off a replacement drive. The server will be replaced over the coming weeks, (which means there will be a short outage again, at that point).
The carousel had to be rebuilt - which happens automatically, but it does mean that the files there may be received again, if you had received them before the crash. Also, file iteration counts were reset, so some of the older files will be going around a bit more frequently than they should over the next day or two.
Why it takes so long: the "backend" is a dedicated, specialized box, not a generic server. Its located at a European teleport. Everything has to be done remotely, including finding a temporary replacement for the drive, finding someone to swap it out, and then having to restore the box image remotely.
I do agree about the SSDs though - I my experience their failures are more frequent than spinning disks. Spinning disks also are better at warning about imminent failure. But there are obvious advantages as well - as @neil already mentioned. No, its not a PC. Yes, RAID isn't currently a feature on the hardware. Thats something we are taking up and want to resolve in the replacement box.
I am told that this is the first time ever a drive has failed in such a box. So theres that.