The file server is unaware of normal Plan 9 partitions. The DOS code has some minimal awareness of fdisk partitions, but in general you should use whole disks or the `p' device to subdivide them. The DOS code only knows how to read FAT 12 and FAT 16 file systems. If you want to see what's happening in the DOS code, change the definition of `chatty' at /sys/src/fs/pc/dosfs.c:16 to
#define chatty 1 and build and boot a new kernel. The nvr/DOS code is a little different than the usual block I/O code in the file server. nvrdevs[] in /sys/src/fs/fs64/9fsfs64.c (or whatever it's called for your file server) contains different entry points than the usual ones.
