Re: Do user processes apply against shmmax limit?

Tim,

Unless shared servers (MTS) are in use, in which case either the UGA or PGA is in the SGA.

To be honest, I can't recall which, and I'm too lazy to go look it up right now. But MTS will consume memory on a per user basis, though the poster didn't mention it. And I'm quite sure you know this, but thought I would mention for the benefit of those on the list that don't know that.

Let one of them look it up. :)

Also, the vmstat stats show PI/PO at very low rates, and the SR ( scan rate ) is mostly zero.

Jay, Ask your SA "Where's the memory problem?"

Jared

On Saturday 23 November 2002 11:38, Tim Gorman wrote:
> Your Sys Admin is wrong. The SHMxxx OS parameters refer to "shared
> memory", not private process heap memory. On most UNIX variants, the
> "ulimit" command is used to limit the consumption of memory for heap,
> stack, etc...
>
> ----- Original Message -----
> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>
> Sent: Saturday, November 23, 2002 11:48 AM
>
> > Hi everyone,
> >
> > I was always under the impression that the only concern with shmmax was
>
> that
>
> > it be large enough for the SGA to fit into it. One of my System
> > Administrators has just told me that the individual user processes (i.e.,
> > the PGA since we're not using multi-threaded server) get added to the SGA
> > and if that SGA + user processes > shmmax the system will start swapping.
> >
> > I haven't found anything to specifically address this issue on Metalink
> > so
>
> I
>
> > though I'd throw it open. We've started experiencing system slowdown and
>
> he
>
> > says that increasing shmmax could resolve it. I'm skeptical (he also
> > suggested increasing SGA to decrease swapping which I told him in no
> > uncertain terms was nonsense).
> >
> > If anyone has a link to a note or white paper I'd appreciate that too.
> >
> > I've appended his email at the bottom. This slowdown seems to occur even
> > when there's virtually on oracle activity so I'm suspecting some other
> > cause.
> >
> > Thanks,
> > Jay Miller
> >
> >
> >
> >
> > nycsun1 and njsun7 has 6 GB of memory and only 2 GB of share memory. This
> > morning nycsun1 was very slow and I noticed that there was lots of
>
> swaping.
>
> > see vmstst and iostat below in red:
> >
> > procs memory page disk faults cpu
> > r b w swap free re mf pi po fr de sr s2 s4 s4 sd in sy cs us
>
> sy
>
> > id
> > 0 0 23 4366736 97528 1 2186 16 12 12 95520 0 0 0 0 0 1104 3330 974 11
>
> 8
>
> > 81
> > 0 0 23 4365992 96056 1 451 16 24 52 85968 3 0 0 0 0 935 847 416 3
>
> 1
>
> > 96
> > 0 0 23 4364712 95512 2 310 36 24 492 85968 68 0 0 0 0 1036 2183 670 13
>
> 4
>
> > 84
> > 0 0 23 4361568 95488 9 2264 0 76 964 95520 136 0 0 0 0 979 4065 607 12
>
> 6
>
> > 82
> > 0 0 23 4362384 96080 1 6 4 8 8 77376 0 0 0 0 0 975 465 457 2
>
> 1
>
> > 97
> > 0 0 23 4361944 95712 4 730 92 48 532 95520 64 0 0 0 0 1040 1859 734 8
>
> 3
>
> > 89
> > 0 0 23 4360424 95480 4 41 36 40 100 77376 7 0 0 0 0 986 1250 542 6
>
> 0
>
> > 94
> > 0 0 23 4361304 96096 3 264 76 36 88 88496 7 0 0 0 0 1037 942 665 5
>
> 3
>
> > 92
> > 0 0 23 4359680 95784 2 449 4 28 84 95520 8 0 0 0 0 922 1047 374 4
>
> 1
>
> > 95
> > 0 0 23 4359936 95464 2 544 4 20 332 95520 44 0 0 0 0 931 1095 384 2
>
> 2
>
> > 96
> >
> > /s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
> > 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c2t6d0
> > 0.0 34.5 0.0 270.0 0.2 13.8 6.7 399.5 6 44 c5t12d0 -- swap
> > disk
> > 0.0 34.5 0.0 270.0 0.5 10.7 15.5 309.4 18 39 c5t13d0 -- swap
> > disk
> >
> >
> > This shows that the system is not effectively using memory. I suggest
> > increasing the share memory to 4 GB so that DBAs can increase their
> > memory usage. Also set priority paging on. Priority paging will give
> > application first priority then free memory will be allocated to file
> > cache( Solaris
>
> 2.6
>
> > and 7. Solaris 8 is set dynamically).
> >
> > * ORACLE CONFIGS
> > set shmsys:shminfo_shmmax =2048000000 -- increase to 4096000000
> > set shmsys:shminfo_shmmin=1
> > set shmsys:shminfo_shmmni=300
> > set shmsys:shminfo_shmseg=30
> > set semsys:seminfo_semmap=500
> > set semsys:seminfo_semmni=200
> > set semsys:seminfo_semmns=2000
> > set semsys:seminfo_semmsl=1000
> > set semsys:seminfo_semmnu=500
> > set semsys:seminfo_semume=150
> >
> >
> >
> > --
> > Please see the official ORACLE-L FAQ: http://www.orafaq.com
> > --
> > Author: Miller, Jay
> > INET: JayMiller_at_TDWaterhouse.com
> >
> > Fat City Network Services -- 858-538-5051 http://www.fatcity.com
> > San Diego, California -- Mailing list and web hosting services
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Jared Still
  INET: jkstill_at_cybcon.com

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