Linux uses all ram for file caching if applications don't use it.
That's how it works. If you aren't using swap and your mahcine is
running fine everything's cool
tblader wrote:
Hello all.
I have a centos 4.4 box (2.6.9-42.0.10.ELsmp) with 7gig of ram that
doesn't seem to be using swap (also 7gig now). I say "seem" because
I've noticed ram utilization run around 95% (with oracle and friends
running) and then firing up a couple apps to use that last 5% will
stop the machine dead in it's tracks.
I ran across some reading[0] about /proc/sys/vm/swappiness and how it
affects the kernels decisions when dealing with swap, but it's not
all that clear to me whether this is the source of the problem.
It seems like the kernel just isn't using swap at all.
I've double checked my swap partition in fstab, ran mkswap again,
double checked it's availability with vmstat -s but still it's
just not getting used. Sunday, the box died around 3am and sar
seems to show memory use on the rise right up till it hurled[1]
(I just stuck another gig in the box monday, so sar only shows
6gig on sunday)
Anyone know whats up with this?
PS: swap is an LVM partition.
Thanks
Thomas
[0] - http://lwn.net/Articles/83588/
[1] - sar -A
12:00:01 AM kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree
kbswpused %swpused kbswpcad
...
02:40:01 AM 197656 5909384 96.76 203308 4066344
16383992 0 0.00 0
02:50:01 AM 191728 5915312 96.86 203320 4066400
16383992 0 0.00 0
03:00:01 AM 185584 5921456 96.96 203336 4067132
16383992 0 0.00 0
03:10:01 AM 185712 5921328 96.96 203344 4067872
16383992 0 0.00 0
Average: 191895 5915145 96.86 203221 4063819
16383992 0 0.00 0
12:00:01 AM pswpin/s pswpout/s
...
02:00:01 AM 0.00 0.00
02:10:01 AM 0.00 0.00
02:20:01 AM 0.00 0.00
02:30:01 AM 0.00 0.00
02:40:01 AM 0.00 0.00
02:50:01 AM 0.00 0.00
03:00:01 AM 0.00 0.00
03:10:01 AM 0.00 0.00
Average: 0.00 0.00
--
My "Foundation" verse:
Isa 54:17 No weapon that is formed against thee shall prosper; and
every tongue that shall rise against thee in judgment thou shalt
condemn. This is the heritage of the servants of the LORD, and their
righteousness is of me, saith the LORD.
-- carpe ductum -- "Grab the tape"
CDTT (Certified Duct Tape Technician)
Linux user #322099
Machines:
206822
256638
276825
http://counter.li.org/
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