[Beowulf] SSD prices

[Lux, James P]

>
> Hmm, I was thinking that until I read this blog post by one
> of the kernel filesystem developers (Val Henson from
> Intel) who had some (possibly Apple specific) concerns about
> data corruption & reliability and why she still chooses
> spinning disks over SSD.
>
> http://valhenson.livejournal.com/25228.html
>
> This is one of the reasons I'm *really* interested to get
> btrfs going on my Dell E4200 which has a 128GB SSD, data
> checksums (and duplicate copies of data) are good..
>

She raises some interesting points, the most significant of which is that "real data" is very hard to come by.  We are starting to use Flash memory for storage on spacecraft, and, of course, wear-out is a big deal. OTOH, it's something we know how to deal with (since spacecraft like Galileo used magnetic tape for storage), even when the medium gets old and decrepit.  There's also some traps for the unwary for flash that don't apply to mechanical storage: What if a software bug hammers on one location accidentally, and whips through all 100,000 cycles of its life in a day?

Of course, in the space biz, we don't have the issue she identifies of different suppliers.  Hah.. We have "traceability to sand", and if someone finds out that a contaminated cigarette butt was dropped on that sand back in 1953, we'll get an alert for all parts potentially made from that sand. (Real fun when the part is something like a 2N2222 NPN transistor or a 51 ohm resistor)