So it's been a few days since I swapped in the Zonbu I bought, as my ATA over Ethernet "head".
It hasn't been all ponies and roses, but it hasn't been a total loss either.
The main problem I was having was a lot of
usb 5-2: reset high speed USB device using ehci_hcd and address 2
type of errors during moderate I/O to the RAID10, which was connected to the four USB ports on the back of the unit (similar errors for all four USB devices). Initial Googling suggested that it was a USB mass-storage thing, and that lowering the maximum number of sectors read (and/or written?) a once in /sys/block/sd[a-d]/device/max_sectors would fix the problem. Well that didn't really seem to make a difference.
Then I did some rummaging in the Zonbu forums, and it became apparent that there were some problems with the four USB ports on the back of the unit and USB 2.0 mass-storage devices.
One of the forum threads pointed me at this bug, which had been subsequently fixed in a newer release of the Zonbu OS. I apprehensively emailed the Zonbu support folks lateish on Friday evening, not expecting to hear anything back until Monday, and half expecting to be unsupported because I was running Debian on it, when I got a reply fairly promptly telling me this kernel patch would fix the problem. It turns out that the VIA CX700 is a wee bit buggy, or the BIOS support for it is or something.
Anyway, I spent the better part of two days compiling a new Debian 2.6.22 kernel with this patch applied (took me two goes, the first time the patch wasn't applied), but the Zonbu is now running a 2.6.22 kernel with this patch.
Notably you get this message during bootup now:
PCI: VIA CX700 PCI parking/caching fixup on 0000:00:11.7
It's a bit early to tell how it's going to work out. I don't have a scheduled recording until tonight, but I've just scheduled something random to see how it works out. Playing back a recording made before I swapped the Zonbu in seemed to go fine.