Re: Memory issue on FreeBSD

FYI
http://freebsd.1045724.n5.nabble.com/Postgresql-related-memory-question-td5759467.html

Am 2012-11-07 10:28, schrieb Achilleas Mantzios:
> On Τετ 07 Νοε 2012 09:42:47 Frank Broniewski wrote:
>> Hey, this is really cool. I directly tried the script and there's a line
>> from the output that caught my eye:
>>
>> > mem_gap_vm: + 8812892160 ( 8404MB) [ 26%] Memory gap: UNKNOWN
>>
>> is this the shared buffers? I guess so, but I want to confirm my guess ...
>
> Hmm, that would be ideal, (from an understanding perspective) but at least in my system (FreeBSD-8.3), no.
>
> psql -q -t -c "show shared_buffers" | grep -v -e '^$' | awk '{print $1}'
> 3840MB
>
> SYSTEM MEMORY INFORMATION:
> mem_gap_vm: + 996843520 ( 950MB) [ 5%] Memory gap: UNKNOWN
>
> $mem_gap_vm = $mem_all - ($mem_wire + $mem_active + $mem_inactive + $mem_cache + $mem_free);
>
> mem_all is some rounded and more rationalized version less than hw.physmem : $mem_all = $sysctl->{"vm.stats.vm.v_page_count"} * $sysctl->{"hw.pagesize"};
>
> Anyway, this is not so postgresql related at the moment. The correct thing to do (since you run production servers on FreeBSD) is to post to the relevant
> FreeBSD list and/or forum. freebsd-questions(at)freebsd(dot)org and freebsd-stable(at)freebsd(dot)org would be a good start.
> Also the forums : http://forums.freebsd.org/forumdisplay.php?f=3
> Only after gathering substantial info from there, would it make sense to come back here and maybe ask more questions.
> And since we are observing different percentages of gaps (mine is 5%, yours is 26%), i think maybe you should look into it on the FreeBSD camp.
>
> Please drop the link to the relevant thread there, if you decide to do so.
>
> I would like to follow this.
>
> Thanx!
>
>>
>> Frank
>>
>> Am 2012-11-07 09:26, schrieb Achilleas Mantzios:
>>> Vick,
>>> fantastic script, thanx! FreeBSD sysctl system is awesome!
>>>
>>> On Τρι 06 Νοε 2012 14:33:43 Vick Khera wrote:
>>>
>>>
>>>
>>> On Mon, Nov 5, 2012 at 10:11 AM, Frank Broniewski <brfr(at)metrico(dot)lu> wrote:
>>>
>>> and this is after a few hours of running:
>>>
>>> Mem: 91M Active, 17G Inact, 3983M Wired, 1526M Cache, 3283M Buf, 155M Free
>>> Swap: 4096M Total, 828K Used, 4095M Free
>>>
>>>
>>>
>>>
>>> For comparison, here is the output of a 32GB FreeBSD 9.0/amd64 server, with Postgres 9.0.7 running since June 10, and is heavily pounded on 24x7. The data + indexes are about 240GB on disk. This server only runs postgres aside from the basic system processes.
>>>
>>>
>>> Mem: 231M Active, 21G Inact, 3777M Wired, 1009M Cache, 3285M Buf, 191M Free
>>> Swap: 4096M Total, 272K Used, 4096M Free
>>>
>>>
>>> I agree with the conclusion that the shared memory segments are confusing the output of top. There are no memory leaks, and FreeBSD doesn't "lose" any memory.
>>>
>>>
>>> There are some scripts floating around that read values from sysctl vm.stats.vm and format them nicely to tell you how much memory is used up and free. Try the one referenced here: http://www.cyberciti.biz/faq/freebsd-command-to-get-ram-information/
>>>
>>>
>>>
>>>
>>>
>>> -
>>> Achilleas Mantzios
>>> IT DEPT
>>>
>>
>>
>>
> -
> Achilleas Mantzios
> IT DEPT
>

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Frank BRONIEWSKI

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