is pg_standby over nfs expected to work?

I have been experimenting with pg_standby with the primay copying
files to a nfs folder mounted from a special server on the standby.
Inevitably, the following happens:

LOG:  restored log file "0000000100000000000000E7" from archive
LOG:  restored log file "0000000100000000000000E8" from archive
LOG:  restored log file "0000000100000000000000E9" from archive
LOG:  could not fsync segment 0 of relation 1663/21119/2673: No such
file or dir  ectory
CONTEXT:  xlog redo checkpoint: redo 0/E9047EC8; undo 0/0; tli 1; xid
0/20369249  ; oid 24584; multi 1; offset 0; online
FATAL:  storage sync failed on magnetic disk: No such file or directory
CONTEXT:  xlog redo checkpoint: redo 0/E9047EC8; undo 0/0; tli 1; xid
0/20369249  ; oid 24584; multi 1; offset 0; online
LOG:  startup process (PID 30031) exited with exit code 1
LOG:  aborting startup due to startup process failure
LOG:  logger shutting down

I'm thinking one of two things is wrong, either I'm not mounting the
nfs folder in a suitable way to do this, or I have to revert to
shipping wal files with nc.  anybody have any ideas?

merlin