IPv6 NFS performance

[Francois Tigeot <ftigeot@xxxxxxxxxxxx>]

Hi all,

I have recently setup a NFS share with IPv6 addresses on a gigabit lan. The
performance is abysmal: 500 KB/s max.

The same server and client on the same lan, have no trouble reaching tens of
MB/s.

Time spent copying some big files from the server to a local disk:

v4: sent 86109382 bytes  received 31 bytes  24602689.43 bytes/sec
v6: sent 49660678 bytes  received 31 bytes  266277.26 bytes/sec

All mounts were using tcp.

IPv6 speed is about 100 time slower than IPv4.

I don't believe I'm doing anything wrong. How can I diagnose/fix this issue ?

-- 
Francois Tigeot