Re: how much swap for 10g on a 4Gb RAM system?

From: DA Morgan <>
Date: Thu, 31 Jul 2008 17:12:18 -0700
Message-ID: <>

Palooka wrote:

> joel garry wrote:

>> On Jul 29, 12:19 pm, Palooka <> wrote:
>>> obakesan wrote:
>>>> Hi
>>>> I'm just going through installing 10g and wondered about the swap
>>>> requirements. The documents I'm reading suggest:
>>>> " Swap space should be twice the amount of RAM for systems with 2GB of
>>>> RAM or less and between one and two times the amount of RAM for
>>>> systems with
>>>> more than 2GB. "
>>>> Since I've got 4 Gig, do I really need 4Gig of Swap? I'm not
>>>> pressing this
>>>> system as its just a "learning" platform.
>>>> Has anyone got any experience with trying this with less:
>>>> $ grep -i swaptotal /proc/meminfo
>>>> SwapTotal: 2031608 kB
>>> Surely it can't hurt just to follow the instructions, can it?
>>> Palooka
>> Yes, it can. It can hurt a lot. That's why the instructions change
>> over time, and sometimes do not reconcile between release notes,
>> installation guides and metalink notes. Platform specific issues can
>> be especially irritating, and the range of configuration issues over
>> various linux releases is quite broad.
> Joel,
> I confess to being a little surprised at this. If Oracle say double the 
> RAM, why not just do so? A few gig of disk space is surely neither here 
> nor there nowadays. Can you elucidate?
> Palooka

Because sometimes throwing more resources at a problem makes it worse. Jonathan Lewis has a great example he uses where increasing sort area causes more memory to be swapped to disk: Not a good thing. There are many other case study examples of this behavior.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Thu Jul 31 2008 - 19:12:18 CDT

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