Hi all–
We seem to have everything working ok now. Journaling was enabled for the Xserve drives, so I turned that off, and I also repaired permissions for drives.
I also used an Io Easy Setup preset instead of the custom setup that had been selected (someone other than Carrie and myself had configured the setup of the Io, obviously incorrectly)
So now everything’s capturing fine. No more delay before capture with the “Allocating Disk Space” tagline & then the subsequent dropped frames. The clips that are captured all need to be rendered in FCP (no RT, but that makes sense seeing as it’s all uncompressed footage), but we’re happy with the results.
Thanks again everyone for your help!