[TriLUG] a Ferrari in a traffic jam (was: why is it slow?)

[Alan Porter]

> initially, i thought it was because i uploaded all those pictures to 
> the server and it needed to be defraged?? (can you defrag a linux 
> harddrive? if so how)

Under normal circumstances, you should never have to de-frag
a Linux filesystem.  Just Google for "defrag Linux", and you'll
get a lot of links like this:

http://www.extremetech.com/article2/0,1697,1455687,00.asp

When someone complains about a computer system being "slow", a
lot of well-intentioned people will offer quick fixes such as
"a faster CPU" or defragging the disk.  These seldom fix the
original problem.

As I like to say, you have a Ferrari in a traffic jam.

Your hardware and your filesystem are really fast (on the order
of milliseconds, not in 10's of seconds).  But the CPU is waiting
for system until it times out.

One usual suspect is the network.  DNS mis-configurations can
cause frequent timeouts.  Your other statement about the difference
between the 71.71.xx.xx network and the 192.xx.xx.xx network also
points in this same direction.

Sorry, I have no specific advice to offer for your problem.
I just needed to rant about defragging and faster CPU's.


Alan