Re: Swapping Issues and ora_dbw
- From: Frits Hoogland <frits.hoogland@xxxxxxxxx>
- To: "jcoll1970@xxxxxxxxx" <jcoll1970@xxxxxxxxx>
- Date: Thu, 9 Oct 2014 19:50:42 +0200
Except for PGA, which doesn't use hugepages (at least on Linux)
Frits Hoogland
http://fritshoogland.wordpress.com
frits.hoogland@xxxxxxxxx
Office : +31 20 5939953
Mobile: +31 6 14180860
(Sent from my iPhone, typo's are expected)
> Op 9 okt. 2014 om 19:39 heeft Joshua Collier <jcoll1970@xxxxxxxxx> het
> volgende geschreven:
>
> look into enabling huge pages for your system. it will eliminate all
> possibility of swapping when properly configured. with this OS Linux
> 2.6.39-400.210.2.el5uek you should have huge pages set up.
>
> How much ram on the server total?
>
>> On Wed, Oct 8, 2014 at 12:26 AM, Hilton Meyer <hilton@xxxxxxxx> wrote:
>> Thanks for the suggestions folks. I looked at the PGA and SGA targets and
>> they were super high.
>>
>> I lowered them to SGA Target 4GB and PGA Target 2GB on each of the instances
>> and restarted.
>>
>> Things look better already and I'll keep an eye on the issue.
>>
>>
>>
>> Thanks again for the help,
>>
>>
>>
>> Hilton Meyer
>>
>> Database Administrator
>>
>>
>>
>> Phone: +972-52-7908599
>>
>> Office: +972-52-7908600 Fax: 1535-27908600
>>
>> hilton@xxxxxxxx | www.komit.co
>>
>>
>>
>> <image001.png>
>>
>>
>>
>> From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
>> On Behalf Of Hilton Meyer
>> Sent: Wednesday, October 08, 2014 8:29 AM
>> To: Mark W. Farnham; oracle-l@xxxxxxxxxxxxx
>>
>>
>> Subject: RE: Swapping Issues and ora_dbw
>>
>>
>> Here is the full commands and outputs:
>>
>>
>>
>> # top –c
>>
>> top - 08:15:23 up 26 days, 21:15, 4 users, load average: 1.80, 2.20, 2.55
>>
>> Tasks: 613 total, 5 running, 608 sleeping, 0 stopped, 0 zombie
>>
>> Cpu(s): 20.3%us, 3.9%sy, 0.0%ni, 68.2%id, 7.4%wa, 0.0%hi, 0.1%si,
>> 0.0%st
>>
>> Mem: 49557132k total, 49264636k used, 292496k free, 49236k buffers
>>
>> Swap: 8257532k total, 7888592k used, 368940k free, 42721744k cached
>>
>>
>>
>> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
>>
>>
>> 49069 oradev 20 0 12.2g 10g 9g S 0.0 21.2 41:58.61 ora_dbw0_DEV
>>
>>
>> 49073 oradev 20 0 12.2g 9g 9g S 0.0 21.1 41:58.67 ora_dbw1_DEV
>>
>>
>> 4716 orapatch 20 0 12.2g 8.5g 8.5g S 0.0 17.9 34:21.58 ora_dbw1_PATCH
>>
>>
>> 4712 orapatch 20 0 12.2g 8.5g 8.4g S 0.0 17.9 32:42.16 ora_dbw0_PATCH
>>
>>
>> .
>>
>> .
>>
>> .
>>
>>
>>
>> # free -m
>>
>> total used free shared buffers cached
>>
>> Mem: 48395 48106 288 0 55 41525
>>
>> -/+ buffers/cache: 6525 41870
>>
>> Swap: 8063 7724 339
>>
>>
>>
>> Thanks,
>>
>>
>>
>> Hilton Meyer
>>
>> Database Administrator
>>
>>
>>
>> Phone: +972-52-7908599
>>
>> Office: +972-52-7908600 Fax: 1535-27908600
>>
>> hilton@xxxxxxxx | www.komit.co
>>
>>
>>
>> <image001.png>
>>
>>
>>
>> From: Mark W. Farnham [mailto:mwf@xxxxxxxx]
>> Sent: Tuesday, October 07, 2014 5:40 PM
>> To: Hilton Meyer; oracle-l@xxxxxxxxxxxxx
>> Subject: RE: Swapping Issues and ora_dbw
>>
>>
>>
>> 1) tell us the command (some variety of ps?)
>>
>> 2) give us a head -2 of the command results so we can see the headings as
>> well as the lines you care about
>>
>> 3) without knowing the tool, is it one that reports the combined sum of
>> memory used by the process as well as any shared memory attached during its
>> run? IF so, then easily up to your sga size could be a complete red herring
>> in considering the amount of memory a process is holding
>>
>>
>>
>> From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
>> On Behalf Of Hilton Meyer
>> Sent: Tuesday, October 07, 2014 5:25 AM
>> To: oracle-l@xxxxxxxxxxxxx
>> Subject: Swapping Issues and ora_dbw
>>
>>
>>
>> Hi there,
>>
>>
>>
>> I have a test server with three instances running and I have been seeing
>> that swapping issues.
>>
>> The server is running out of swap space, been flirting on the edge of 0.
>>
>> I dug a little deeper an found that the main culprits are two of the
>> instances:
>>
>>
>>
>> 49069 oradev 20 0 12.2g 10g 10g S 0.0 21.5 40:44.19 ora_dbw0_DEV
>>
>>
>> 49073 oradev 20 0 12.2g 10g 10g S 0.0 21.5 40:43.90 ora_dbw1_DEV
>>
>>
>> 4716 orapatch 20 0 12.2g 8.5g 8.5g S 0.0 17.9 33:20.19 ora_dbw1_PATCH
>>
>>
>> 4712 orapatch 20 0 12.2g 8.4g 8.4g S 0.0 17.9 31:45.49 ora_dbw0_PATCH
>>
>>
>>
>> The weird thing is the third instance does not register although they are
>> the same clone from the Production instance.
>>
>> Few questions:
>>
>> · Is this not an unusually high percentage of memory for the process
>> to hold?
>>
>> · Is there a way to release the memory back to the server?
>>
>> · Is there a way for me to dig deeper to find out why these two
>> instances are holding so much memory?
>>
>>
>>
>>
>>
>> Sys Info:
>>
>> EBS R12.1.3
>>
>> Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
>>
>> Linux 2.6.39-400.210.2.el5uek
>>
>>
>>
>> Thanks,
>>
>>
>>
>> Hilton Meyer
>>
>> Database Administrator
>>
>>
>>
>> Phone: +972-52-7908599
>>
>> Office: +972-52-7908600 Fax: 1535-27908600
>>
>> hilton@xxxxxxxx | www.komit.co
>>
>>
>>
>> <image001.png>
>>
>>
>>
>
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