My thought has been that if my system is using more than 20GB of swap isn't it likely to be spending more cycles dealing with moving pages in and out of swap than anything else? I have a huge number of 96GB RHEL5 boxes & the only time I ever see them use swap is when something has gone haywire & then it wouldn't matter if I have 8 or 300 it just would take longer to fill up. -- Bryce T Pier Sent from my Android phone.
"Singer X.J. Wang" <[email protected]> wrote: Actually that is not the Oracle recommendations. The current 11g guidelines call for a fixed 16GB swap size if the RAM is greater then 16GB. http://download.oracle.com/docs/cd/B28359_01/install.111/b32002/pre_install.htm#CHDCEBFF Singer On Wed, Apr 20, 2011 at 09:38, Adam Tauno Williams <[email protected]> wrote: On Wed, 2011-04-20 at 06:25 -0700, Andrew Hume wrote: > i know, i know. this is an old chestnut. > we used to have swap 2-3x main memory, > but nowadays the wisdom is that that old rule > is no longer applicable. (this is on RHE5.) > so here i am, with a 128GB memory system with 16GB of swap. > and here i am, killing the system by running it out of swap. > my observation is that if i have large memory, i will use it. > (to say nothing of memory leaks etc.) > and if i have a few multiple large memory processes, > why wouldn't i want swap sized at 2-3x memory? Most recommendations I see [in professional notes and documentation, not general Internet-swill] point to SWAP = 0.75 * RAM for systems with more than 8 GB of memory. This is the RHEL & Oracle recommandations at least, but I've seen it other places. You also might get some benefit from playing with the /proc/sys/vm/swappiness value. -- Adam Tauno Williams <[email protected]> LPIC-1, Novell CLA <http://www.whitemiceconsulting.com> OpenGroupware, Cyrus IMAPd, Postfix, OpenLDAP, Samba _______________________________________________ Tech mailing list [email protected] https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/ -- The best compliment you could give Pythian for our service is a referral.
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