Odd swap & memory behavior on Solaris 9, Oracle 9iR2
- From: "Matthew Zito" <mzito@xxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Mon, 17 Apr 2006 11:23:12 -0400
Howdy folks,
A friend of mine is seeing something odd on their Solaris 9/Oracle 9iR2
environment. They were having problems swapping constantly, and they gave me a
call. They had their SGA + number of sessions * PGA sized significantly larger
than their physical RAM, so I recommended they back everything down. However,
the really odd behavior they see is that when they start up the Oracle
instance, an amount of swap equivalent to their SGA is allocated, even when
there's tons of free physical memory. Looking around metalink produced this
little snippet from Note 151222.1:
"In Solaris 8, thanks to DISM support (Dynamic Intimate Shared Memory), it is
possible to avoid the above limitation and allocate the shared memory segment
such that only the active granules in the SGA are located in physical memory.
All unused granules will be stored in swap until needed.
NOTE: Swap space for the entire SGA_MAX_SIZE is required. See Note 230453.1
for more details."
However, note 230453.1 doesn't exist anymore. I tested a similar config on a
Solaris 8 box we have in our lab, and a similar behavior was not evidenced.
Anyone have ideas where we should be looking?
Thanks,
Matt
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