[Lustre-discuss] [HPDD-discuss] will obdfilter-survey destroy an already formatted file system

[Michael Kluge]

Hi Cory,

I am running this stuff now since a few weeks. Only a few users are using the file system up to now. Either I was lucky or Andreas is right. No one has complained yet that data got lost. I am running integrity checks in parallel and they did not find anything yet. So we can say it is "most probably safe" :)


Regards, Michael


> Michael,
> 
> Unfortunately, the current Lustre Ops Manual indicates the opposite.  From
> section 24.3 "Testing OST Performance (obdfilter_survey)":
> 
> "The obdfilter_survey script is destructive and should not be run on
> devices that containing existing data that needs to be preserved. Thus,
> tests using obdfilter_survey should be run before the Lustre file system
> is placed in production."
> 
> I opened LUDOC-146 to track the issue previously and updated the details
> to include Andreas' explanation.
> 
> Thanks,
> -Cory
> 
> 
> On 3/21/13 7:18 PM, "Dilger, Andreas" <andreas.dilger at intel.com> wrote:
> 
>> On 2013/21/03 4:09 AM, "Michael Kluge" <Michael.Kluge at tu-dresden.de>
>> wrote:
>>> I have read through the documentation for obdfilter-survey but could not
>>> found any information on how invasive the test is. Will it destroy an
>>> already formatted OST or render user data unusable?
>> 
>> It shouldn't - the obdfilter-survey uses a different object sequence (2)
>> compared to normal filesystem objects (currently always 0), so the two do
>> not collide.
>> 
>> Cheers, Andreas
>> -- 
>> Andreas Dilger
>> 
>> Lustre Software Architect
>> Intel High Performance Data Division
>> 
>> 
>> _______________________________________________
>> HPDD-discuss mailing list
>> HPDD-discuss at lists.01.org
>> https://lists.01.org/mailman/listinfo/hpdd-discuss
>