The man page for mount lists the default rsize and wsize for NFS mounts to
be 1024 when it is 4096. Looking at include/linux/nfs_fs.h from the
2.2.14-5.0 source, NFS_DEF_FILE_IO_BUFFER_SIZE is set to 4096. From
fs/nfs/nfsroot.c, nfs_data.r/wsize gets set to this const. Tcpdump
verifies this. I have not yet checked pinstripe.
Fixed in 2.10o-1