Re: quick linux memory question

From: Kenny Payton <>
Date: Mon, 31 Mar 2014 14:51:31 -0400
Message-Id: <>

I would say both are a little small considering the amount of memory on the host depending on the servers use case. Also, I would expect SHMALL ( * pagesize ) to be higher than SHMMAX since SHMALL is total system wide shared memory and SHMMAX is the maximum size of any single segment.

If not already you might also want to look into huge pages, especially if you’re running a large SGA and a large number of connections.

On Mar 31, 2014, at 2:40 PM, Sweetser, Joe <> wrote:

> All -
> Red Hat Enterprise Linux Server release 5.8 (Tikanga)
> Oracle 11.1 and 11.2 databases
> 252gb main memory
> Page_size = 4096 (bytes)
> Shmmax = 76800000000 (bytes)
> shmall = 4194304 (pages)
> I am sort of referencing Doc ID 301830.1
> So, shmmax is about 71.5gb and shmall is currently set to use up to 16gb of 'SGA' space (my term).
> Sanity check: any issue with setting shmall to something like 15728640 (60gb)? Still well below physical memory and somewhat below shmmax, but I have never set shmall that high so just curious if there any gotchas.
> ADVthanksANCE,
> -joe
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Received on Mon Mar 31 2014 - 20:51:31 CEST

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