William L. Maltby wrote:
On Sun, 2006-06-04 at 09:57 -0400, Sam Drinkard wrote:
William L. Maltby wrote:
On Thu, 2006-06-01 at 19:18 -0400, Sam Drinkard wrote:
Johnny,
After reading about the VM issue, I concur. <snip>
I forget the start of this thread... was 64 bit only? Anyway, I had my
32bit lock a couple times with symptoms like Sam mentions. Lots of swap
used and no reason for it. Was using lots of open browsers, a couple
different GUI MUAs, etc.
Turned off things I didn't need <snip>
A *biggie*, maybe, is the stupid readahead and readahead_early stuff.
<snip>
Up now for 6 days running similar load (I think, haven't bothered to
really measure it) and swap use is still good and response is still
good.
<snip>
After uptime of a little over 3 days now, I'm not seeing any increase in
swap as I did prior, but then again, I don't exactly recall how long it
took before swap started increasing.
For my symptoms to appear, it took a combo of time up and an increase in
load. Don't know if this is coincidence or cause and effect.
One thing I do notice is for some
reason, the applications that nomally would consume between 1.2 - 1.4G
of memory is now down to 1.1 - 1.2, and swap is only lightly touched at
181mb.
Again, mine is only a workstation, so I don't know how this applies to
you. My max on the previous session was 64k into swap. That was about 4
days up, IIRC and I tried at several points to dupe the conditions
(opened several browsers, multiple users, several different
type/instances of MUAs, several ssh to my LAN server, etc.).
I've since turned sendmail back on so I can do some LAN-internal things
with it. Pretty much stock config except that I removed the restriction
on localhost (a DAEMON_OPTION in the sendmail.mc file). Needed to reboot
to to test LVM config changes (new stuff for me) and after a day and a
half of running, 0k in swap with medium load.
Don't know if this is due to the kernal update or what, but it
would seem logical that it is, since I see different behavior than
previously. I've not turned off readahead or readahead_early yet, but
will do so shortly and see if I can tell any difference in model run
times which did increase after the kernel update. One thing at a time I
guess :-)
Theoretically, there ought to be a decrease in startup times at certain
points _early_in_the_uptime_cycle. IMO, after a "steady state" typical
loading is achieved (hours, day, weeks??) there should be no or reduced
improvement (maybe decreased too *if* this forces some spurious swap
activity?).
*If* your config is anything similar to mine (or any generic?), I doubt
you'll find any long-term gain significant enough to warrant even the
near-zero maintenance of two more scripts and associated files.
It's the old "It doesn't cost me anything, but I get no benefit either"
routine. I almost always opt for excision of the wart. Sometimes that
costs later, but that's OK by me.
Just before the current model run started, I turned off the readahead
and readahead_early, and see a considerable decrease in used memory,
down from 1.2G to about 975 +/-. Unfortunately, the model did not
initialize on time, and I had to bring it up manualy after some input
files were not available, but I can tell by runtime if there has been
any improvement. Normal runtime is about 3.75 hours, and *any*
reduction in runtime would be great. This machine is set up as a
workstation, with X and the whole nine yards going, but there are no
entertainment things used, nor word processing, etc. The only mail is
what I get from the system too, however sendmail is alive and active. I
do have things set if my primary mail machine goes down, I can enable
Evolution on it with a mouse click. There are no other users except for
an ocassional login from a friend who assists in some of the software
running that I am unfamilar with at this point. I do see some processes
that could probably be turned off, but as long as I don't start hitting
swap and thrashing disks, there probably would be no benefit in real
terms to stop these services, and some, I'm not sure I fully understand
what all is taking place either. Currently 150 processes and a load
aveage of 2.32, 2.10, and 2.04 give or take a little.
We'll see what happens this afternoon when the model completes. I'm
hoping for good results.
--
Sam W.Drinkard -- sam@xxxxxxxxxx
http://wa4phy.net
Augusta Area Mesonet
cell 706.825.8513 Home 706.868.7253
MAIL 4428 Branchwood Drive,
Martinez Georgia, 30907-1304
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
