Re: Sun box runs out of swap when starting Oracle

From: joel garry <joel-garry_at_home.com>
Date: Tue, 27 Sep 2011 09:19:19 -0700 (PDT)
Message-ID: <1bf320fb-1f67-4377-ae11-f8f82f45913b_at_5g2000yqo.googlegroups.com>



On Sep 26, 5:24 pm, vsevolod afanassiev
<vsevolod.afanass..._at_gmail.com> wrote:
> After reading a bit more on the subject I've found that Oracle uses
> DISM (Dynamic ISM) pages,
> this can be seen using "pmap -sx":
>
> 0000000380000000       4096       4096          -          -   4M
> rwxs-    [ dism shmid=0x16 ]
> 0000000380400000   15822848          -          -          -    -
> rwxs-    [ dism shmid=0x16 ]
> 0000000746000000     180224     180224          -          -   4M
> rwxs-    [ dism shmid=0x16 ]
> 0000000751000000       8192       8192          -          -    -
> rwxs-    [ dism shmid=0x16 ]
> 0000000751800000       8192       8192          -          -   4M
> rwxs-    [ dism shmid=0x16 ]
>
> There is Solaris paper "Dynamic Reconfiguration and Oracle9i
> Dynamically Resizable SGA",
> it states that Oracle 9i uses DISM if SGA size > size of its
> components which is true in our case.
>
> Experimenting with another database that has 1 GB SGA I was able to
> get it to use ISM instead of DISM
> after increasing db_cache_size:
>
> 000000010362C000          8          8          8          -   8K
> rwx--    [ heap ]
> 0000000380000000    1069056    1069056          -    1069056   4M
> rwxsR    [ ism shmid=0x2000036 ]
> FFFFFFFF7D100000          8          8          8          -   8K
> rwx--    [ anon ]
> FFFFFFFF7D102000          8          -          -          -    -
> rwx--    [ anon ]

This is such a common issue I've been telling people to search for DISM on MOS for any similar memory issue before even bothering with OS tools. I was burned by the similar ISM issue 15 years ago.

jg

--
_at_home.com is bogus.
"This is a very big machine."
http://www.computerworlduk.com/news/infrastructure/3306349/oracle-sparc-supercluster-due-by-end-of-the-year/
Received on Tue Sep 27 2011 - 11:19:19 CDT

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