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-   -   used swap is 0 on some servers (https://www.linuxquestions.org/questions/linux-newbie-8/used-swap-is-0-on-some-servers-4175517012/)

procfs 09-01-2014 12:39 AM

used swap is 0 on some servers
 
Hi, I am bit confused and was trying to get an answer by googling but not what I want... any how below is my question

I have few some servers and I can see some machines using swap and some dome (swap is 0) never changes. Whey is this deference.

Bot are using RedHat linux and 64bib

Thanks and Regards

EDDY1 09-01-2014 01:41 AM

Maybe the work load isn't as heavy on those machines. How much ram is in your machines?
On themachines that don't swap how much of the ram is being used?

procfs 09-01-2014 02:12 AM

Hi EDDY1, yes work loads are different, one with 0 swap is an oracle database and other one is oracle application server. IBM blades with 16Gb each

Regards

EDDY1 09-01-2014 02:20 AM

I would say to check memory usage on both. And yes workload makes a difference. Also swap doesn't get used until there isn't any memory to use.
How much swap are you using percentage wise. If almost all of it then you might want to increase the amount of swap you have.

procfs 09-01-2014 02:48 AM

It goes up to about 30% and stops, this happens during the course of 2 days after a reboot and varies + or - 1% or so. Then again DB server always stays at 0 and never movies. If I to suspect some one has stopped swapping how do I go about investigating since swappiness set at 60 (this is default I think)

Regards

EDDY1 09-01-2014 04:16 AM

Try turning on
Quote:

swapon

jpollard 09-01-2014 09:52 AM

It is possible (haven't use Oracle in years) that oracle locks memory for its own use, and prevents it from being paged out.

jefro 09-01-2014 08:30 PM

Start at top command maybe?

procfs 09-11-2014 06:37 AM

Hi All thanks for the replies but swap is on and swap usage is 0. I am planning on loading one of this server that is running with swap 0 and see if this would change anything :)

Thanks and best regards

jefro 09-11-2014 03:29 PM

Oracle may not use more ram than set to in config.


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