NAS mais rápido no mac ?

Resolving Poor Mac OS X Samba Performance with D-Link’s DNS-323 NAS

Published by Eric Litman on Monday, October 8th, 2007 3:02pm

A few months ago I bought a couple of D-Link’s DNS-323 low-end network attached storage devices as part of my ongoing mission to reduce and simplify the hardware in my home. For about $375 ($175 for the DNS-323 and $100 each for two 500GB hard disks) and almost no setup effort^†, you can have 1/2 TB of redundant storage in a small, quiet, Gigabit Ethernet-capable server with some pretty nifty features out of the box. And if you’re a tinkerer with some Linux experience, you can draw from the thriving hacking community supporting it. For the money, I love these little things.

But while my Windows machines communicate with them without issue, performance with my Macs has been abysmal. Even on an 802.11n network, OS X’s average transfer rate is somewhere around 80KB/s. Fortunately, I tracked the problem down to a tunable network parameter tied to OS X’s FreeBSD roots: net.inet.tcp.delayed_ack.

Under 10.4.10, the default value for delayed_ack is 3. If you’re seeing similar performance issues either with the DNS-323 or other Samba servers in general, try setting it to a value of 0:

sudo sysctl -w net.inet.tcp.delayed_ack=0

I recommend doing this while transferring a large file so you can immediately observe any change in performance. To make this setting permanent, add the following to /etc/sysctl.conf (you may need to create the file):

net.inet.tcp.delayed_ack=0