RE: SWAP Space Confusion Note 1354525.1

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Date: Mon, 28 Jan 2013 12:50:15 -0600
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So, going back to this...
(env RAC on 3 node RHEL 5.6 64-bit)

On a system with 128GB RAM, 100GB SGA, 20 GB PGA, 500 connected sessions (20-30 active), how confident can we be that 16GB of SWAP is sufficient? (side note: RHEL is running at mostly default settings such as vm.swappiness = 60)

I've seen notes all over the place on this and I'm wary setting the swap space too low but also don't want to set aside a large swap area just to have it sitting there doing mostly nothing.


Ref: 10gR2 SWAP Space Requirement For Systems Having Huge RAM [ID 1354525.1]

Per the above doc, the "GOAL" section says: "For Systems having Huge Memory (RAM) is it really required to have SWAP Space as 0.75 X RAM"

Per the Solution it says:
As per the Documentation below is the swap space requirement for 10gR2:

RAM                           Swap Space
===                           =========Up to 512 MB                  2 times the size of RAM
Between 1024 MB and 2048 MB 1.5 times the size of RAM Between 2049 MB and 8192 MB Equal to the size of RAM More than 8192 MB 0.75 times the size of RAM

As part of Unpublished Documentation Bug below are the new values for SWAP Space requirements approved by Oracle Development Team and also updated in 11.1 and 11.2 Install guides as below:

RAM                       Swap Space
===                       =========Between 1 GB and 2 GB     1.5 times the size of RAM
Between 2 GB and 16 GB    Equal to the size of RAM
More than 16 GB           16 GB

All the other pre-requisites mentioned for Oracle Database Software in the installation guide published by Oracle Development Team need to be completed as appropriate.

You may proceed with the swap space requirements as mentioned in the updated guides and ignore any swap related warnings during the installation of 10gR2.

Chris Taylor
Oracle DBA
Parallon IT&S



Niall Litchfield
Oracle DBA


-- Received on Mon Jan 28 2013 - 19:50:15 CET

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