[nylug-talk] Free -m shows 300MB usage after upgrade to 1GB.

[sixtyfourbeets]

Look at the output of 'top' again. Have a look at the 'buffers'
and 'cached' area -- that's probably where the extra memory usage is. "Free"
unused memory is wasted memory, so the Linux kernel caches the hard disk with
the unusued memory. This is not something to worry about; that cache memory
space will free up with "memory pressure", I.E. when running processes ask
for more memory.

 But if you really want to tweak, have a look at the settings
in /proc/sys/vm/ such as /proc/sys/vm/dirty_ratio.

 - Chris

-----------------------------------

Chris thanks for that info.

The reason I upgraded to 1GB in the first place is because I use an application
that is Java based. With Firefox running by itself (3 windows and multiple tabs)
memory usage with 512MB of RAM was at around 100MB.
Once I launched this Java application memory usage spiked considerably
and sometimes
the OS would start to swap when it would retrieve requested data.
I contacted the vendor and they tried to help but they suggested to
upgrade to 1GB, not surprising.
I think every vendor who writes anything in Java uses the following
formula to alleviate any excessive memory
usage, Cliets amount of RAM (or CRAM) * 2.

Warning: Corporate think rant follows
I exchanged emails back and forth about this with them eventually they
kicked it down to their developers.
Their 'lead developer' suggested doubling up on RAM because his
experience showed that 512MB of RAM on a
Windows XP SP2 machine was slow and their file systems fragment too often.  Etc.
He also used that opportunity to subtly try to convince me that I need
an Apple because Apple manages memory better
and the HFS file system doesnt need to be defragged like windowz.
That suggestion discounted the fact that I had mentioned multiple
times in my previous emails that I am running Linux
and that I found that whenever their app was requesting data I found
swap space usage would spike by using
free -m.
I promptly replied by telling him I run Mepis Linux with a Reiser file
system which was the inspiration for Apples OSX,
in fact it if werent for Linux Apple would still be running its 9OS,
whatever that was made of and that OSX'
command line programs are mostly GNU.
He also got an an 'ear full' of my experience of programming with Perl
on Sun Unix, although not stellar but based on their
attention span it might as well be.
The point I wanted to make with that was even if windoz is garbage
that wouldnt discount the fact that Java is a
resource hog.
I hate it when corporate reps try to brainwash me.


Steve M