SATA Native Command Queuing

Matt · *nix forums Guru Wannabe Joined: 05 Mar 2005 Posts: 166

Does Squd perform better with SATA drives that support "Native Command
Queuing"?

http://www.seagate.com/products/interface/sata/native.html

Matt

Gary W. Smith · *nix forums addict Joined: 12 Feb 2005 Posts: 70

This is more of an OS question in the general sense. Anything that can
speed up the drive operations is surely to have a positive impact on the
applications.

My understand of this (from a friend) is that it is possible that an
application could be slower under non-ideal circumstances. That is,
this drive now makes a decision of what data to retrieve when, instead
of just answering OS level requests. The elevator scenario is a good
example of how performance can be increased and decreased as well.

Say you have 100mb of data spread across the disk for squid and there is
a continuous log file or some very random access files (such as a web
server). As file writes are being requested to that log file and data
being request and written to the squid cache, it is possible that the
squid cache would get lower precedence than the rest of the system. The
flip is also true where the squid files are more continuous.

But if this is a dedicated server only housing squid then you would
probably see an improvement as there are no other apps really fighting
for disk time.

Just my $0.02

Gary Wayne Smith

Henrik Nordstrom · *nix forums Guru Joined: 01 Feb 2005 Posts: 2377

tis 2006-07-18 klockan 09:16 -0700 skrev Gary W. Smith:

Google