Art ..
-sh-3.2$ free
total used free shared buffers cached
Mem: 12299204 12071528 227676 0 423980 10159520
-/+ buffers/cache: 1488028 10811176
Swap: 2096472 184 2096288
its the
12299204 12071528
that scares me makes it look like I have zero room left for anything else
-Jeff
Caching the data going to disk actually improves performance because I/O
can be scheduled in larger chunks and be ordered more efficiently to disk.
Also, the cached data is immediately available for processes to use
without going back to the disk to get it. Linux uses most of the memory
it doesn't need for other running processes to cache its disk I/O so
you'll rarely see free memory available on a busy system. The amount of
cache being used can be seen using "free", e.g.:
$ free
total used free shared buffers cached
Mem: 8182268 8135656 46612 0 6888 6748420
-/+ buffers/cache: 1380348 6801920
Swap: 8385920 140580 8245340
The important number to look at is the second line of the "free" column...
this is the actual free memory plus memory being used by buffers/cache
(46612+6888+6748420=6801920), most of which could be made available if
needed by the system to stuff more processes into the system. So, you
could consider this to be effectively free memory... what does your system
show for the second line of the free column?
Art
Gilbert,
what does BillyBob know about a real operating system ;}
system loads are below or just flirting with 1, only time the loads bounce
over 1 is when scour runs
-Jeff
On Sun, 24 Oct 2010, Steve Emmerson wrote:
Jeff,
How do you know the LDM is using the memory?
On a Linux system, the operating-system will consume as much memory as
it can without interfering with user processes.
For the first few years of running Linux, I had wondered the same thing.
Look at your load average, for starters. If you're below 1, chances are
it's all good. 12 GB of RAM is fine, and you'll never use that much. Bill
Gates told me so! ;-)
I have found that running 1.2 GB queue out of /dev/shm for my LDM, even
with level 2 data coming in, works fine. It is on my NOAAport ingest
server, whose load average most of the time is flat out zero. It does jump
up to about .50 when NOAAPort is closer to it's current 10 mb/sec max.
*******************************************************************************
Gilbert Sebenste
********
(My opinions only!) ******
Staff Meteorologist, Northern Illinois University ****
E-mail: sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://weather.admin.niu.edu **
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