So, while I'm no storage expert by far, I do tinker a bit.
Options:
1) figure out to do a hot spare swap on the offending drive- Eh!
2) remove offending drive from areca raid card then clone using software like IFD (image for dos). Replace fresh drive with cloned image. Eh! drive was beyond beyond by this point.
3) Restore saved backup image to new Raid array set created after replacing offending drive. Bingo! This only works if you immediately create an image of your array as soon as a drive starts acting wonky.
That brings me back to life on this dated Areca/HDD Raid setup.
Not near ssd setups but its near original performance which works for me daily.
256mb length
atto_2_4_15_256mb.JPG
1gb length
atto_2_4_15_1gb.JPG