rsync + nfs trouble

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I'm mounting an nfs file system exported from a 5.1/amd64 server on a
5.99.55/amd64 client.
The fstab line is:
nas:/storage/backup      /nas/backup nfs rw,tcp,intr,soft,noauto 0 0

I then try to transfer data from a local file system to the nfs
mounted file system with rsync:
# rsync -av /archive/backup/* /nas/backup/
... after a few minutes at most ...
rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Broken 
pipe (32)
rsync: close failed on "/nas/backup/path/to/dir/.12560.23255c": Interrupted 
system call (4)
rsync: connection unexpectedly closed (57015 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(601) 
[sender=3.0.8]

or

rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Broken 
pipe (32)
rsync: connection unexpectedly closed (451345 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(601) 
[sender=3.0.8]

Has anyone else seen similar problems?
 Thomas