I was doing some filesystem and RAID testing under Red Hat Enterprise Linux 6.0 recently. I came across some weirdness.

Hardware:
Sun X4170m2
48GB memory
F5100 Flash Array with 40 x 24GB FMODs (Flash Module On DIMM, for all intents and purposes it is an SSD)

Software:
Red Hat Enterprise Linux 6.0, 64-bit
bonnie++ (http://www.coker.com.au/bonnie++)
VDBench (http://sourceforge.net/projects/vdbench)

RAID0, 4, 5, and 6 work fine. Now the weirdness.

RAID0 only shows me 24GB of usable space no matter how many FMODs I use (I tried 2, 10, and 20).
Bonnie++ and VDBench both fail.

RAID10 shows all space. Bonnie++ works but VDBench locks up after less than a minute.

Since RAID10 also uses mirroring, I am guessing that there is something amiss there.

Google doesn't pull up anything useful, at least not so far, so if anyone can help shed some light on this issue, I will be most indebted. VirtualBeer will be had!

Thanks in advance!