[Pacemaker] [Question and Problem] In vSphere5.1 environment, IO blocking of pengine occurs at the time of shared disk trouble for a long time.

[Vladislav Bogdanov]

15.05.2013 11:18, Andrew Beekhof wrote:
> 
> On 15/05/2013, at 5:31 PM, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
> 
>> 15.05.2013 10:25, Andrew Beekhof wrote:
>>>
>>> On 15/05/2013, at 3:50 PM, Vladislav Bogdanov <bubble at hoster-ok.com> wrote:
>>>
>>>> 15.05.2013 08:23, Andrew Beekhof wrote:
>>>>>
>>>>> On 15/05/2013, at 3:11 PM, renayama19661014 at ybb.ne.jp wrote:
>>>>>
>>>>>> Hi Andrew,
>>>>>>
>>>>>> Thank you for comments.
>>>>>>
>>>>>>>> The guest located it to the shared disk.
>>>>>>>
>>>>>>> What is on the shared disk?  The whole OS or app-specific data (i.e. nothing pacemaker needs directly)?
>>>>>>
>>>>>> Shared disk has all the OS and the all data.
>>>>>
>>>>> Oh. I can imagine that being problematic.
>>>>> Pacemaker really isn't designed to function without disk access.
>>>>>
>>>>> You might be able to get away with it if you turn off saving PE files to disk though.
>>>>
>>>> I store CIB and PE files to tmpfs, and sync them to remote storage
>>>> (CIFS) with lsyncd level 1 config (I may share it on request). It copies
>>>> critical data like cib.xml, and moves everything else, symlinking it to
>>>> original place. The same technique may apply here, but with local fs
>>>> instead of cifs.
>>>>
>>>> Btw, the following patch is needed for that, otherwise pacemaker
>>>> overwrites remote files instead of creating new ones on tmpfs:
>>>>
>>>> --- a/lib/common/xml.c  2011-02-11 11:42:37.000000000 +0100
>>>> +++ b/lib/common/xml.c  2011-02-24 15:07:48.541870829 +0100
>>>> @@ -529,6 +529,8 @@ write_file(const char *string, const char *filename)
>>>>        return -1;
>>>>    }
>>>>
>>>> +    unlink(filename);
>>>
>>> Seems like it should be safe to include for normal operation.
>>
>> Exactly.
> 
> Small flaw in that logic... write_file() is not used anywhere.

Heh, thanks for spotting this.

I recall write_file() was used for pengine, but some other function for
CIB. You probably optimized that but forgot to remove unused function,
that's why I was sure patch is still valid. And I did tests (CIFS
storage outage simulation) only after initial patch, but not last years,
that's why I didn't notice the regression - storage uses pacemaker too ;) .

This should go to write_xml_file() (And probably to other places just
before fopen(..., "w"), f.e. series).

Vladislav