Re: pg_dump being killed by oom killer

Hello,

2013/10/29 Paul Warren <pw(at)researchresearch(dot)com>

> root(at)www1:/# ulimit -m
> unlimited
>
> And parameters: overcommit_memory and overcommit_ratio.

>
>
> On Tue, Oct 29, 2013 at 1:06 PM, Sergey Klochkov <klochkov(at)iqbuzz(dot)ru>wrote:
>
>> Hello Paul,
>>
>> If so, what does ulimit -m show?
>>
>>
>> 29.10.2013 17:04, Paul Warren пишет:
>>
>>> Hey,
>>>
>>> I think it might not be a issue with pg_dump / db etc but more to do
>>> with proxmox and it's container limits, this is a VM running on proxmox
>>> and could be the cause of the issue. Will look into that first and come
>>> back if it's not.
>>>
>>>
>>> thanks
>>> Paul
>>>
>>>
>>> On Tue, Oct 29, 2013 at 1:01 PM, Sergey Klochkov <klochkov(at)iqbuzz(dot)ru
>>> <mailto:klochkov(at)iqbuzz(dot)ru>> wrote:
>>>
>>> Hello Paul,
>>>
>>> Recently I've run into similar issue, see my message to this mailing
>>> list sent on October 1st, 2013. It happens if there is a large
>>> enough amount of rows in pg_largeobject of the relevant database.
>>> pg_dump loads metadata (owner, access rights, etc) of each large
>>> object deparately until it is out of memory. How many large objects
>>> are in your DB?
>>>
>>> Hope this helps.
>>>
>>> 29.10.2013 16:17, Paul Warren пишет:
>>>
>>> Hi,
>>>
>>> I'm to the lists so bare with me please.
>>>
>>> I have a vm running debian 6 with linux kernel 2.6.32-11-pve,
>>> when i run
>>> pg_dump -Fc -U postgres db name > db name.dump
>>>
>>> after so long the process is killed, when I look in the
>>> /var/log/kern.log i see the following entry
>>> Oct 29 12:07:14 www1 kernel: OOM killed process 0 (pg_dump)
>>> vm:5269904kB, rss:5210224kB, swap:0kB
>>>
>>>
>>> The vm has 16 cpu's and is using around 10%, when I run pg_dump
>>> it goes
>>> up by 3 / 5 % so not using alot of cpu usage. IT has 30gb of ram
>>> and 1gb
>>> of swap, the system uses around 2mb of swap and 15gb of ram, when
>>> pg_dump runs the swap doesn't move but the ram goes up by 3 / 4
>>> gb
>>> before the process is killed.
>>>
>>> The machine had only 20gb of ram so I've increased the ram usage
>>> and
>>> still get the same issue. if I run pg_dump on any other db it
>>> works
>>> fine, if we run a pg_dump script by table on the failing
>>> database it
>>> works fine.
>>>
>>> The backup is going directly to a nas device which has 1.2 tb
>>> free. The
>>> vm has aroudn 40gb free as well.
>>>
>>> Any ideas what this could be? it seems to be a memory issue but
>>> I can't
>>> seem to see what / why it's happening.
>>>
>>> oh the DB is around 1.5 gb / 2gb in size
>>>
>>>
>>> Thanks
>>> Paul
>>>
>>>
>>>
>>> --
>>> Best regards, Klochkov Sergey
>>> www.iqbuzz.ru <http://www.iqbuzz.ru>
>>>
>>>
>>>
>>
>> --
>> С уважением, Клочков Сергей
>> www.iqbuzz.ru
>>
>
>

Best regards
--
JotaComm
http://jotacomm.wordpress.com