[Lustre-discuss] OST threads

[Andreas Dilger]

On 2011-02-25, at 4:37 PM, Mervini, Joseph A wrote:
> That could be awful handy - especially when trying to tune a live file system for performance. Is that going to be a 2.0 only enhancement or can it be applied to existing 1.8 versions?

The patch was originally developed for 1.8, and ported to 2.1.  That said, last time I tested it there were a few problems (crashing variety) so it isn't ready for prime time yet.

Testing/debugging would be appreciated, patch for 1.8 and 2.1 are at:
https://bugzilla.lustre.org/show_bug.cgi?id=22516


> On Feb 24, 2011, at 9:19 PM, Andreas Dilger wrote:
>> Yes, this can be set at startup time to limit the number of started threads. There is a patch I wrote to also reduce the number of running treads but it wasn't landed yet. 
>> 
>> Cheers, Andreas
>> 
>> On 2011-02-24, at 14:04, "Mervini, Joseph A" <jamervi at sandia.gov> wrote:
>> 
>>> I'm inclined to agree. So apparently the only time that modifying the runtime max values has a benefit is while the threads_started is low?
>>> 
>>> Joe
>>> ====
>>> 
>>> Joe Mervini
>>> Sandia National Laboratories
>>> High Performance Computing
>>> 505.844.6770
>>> jamervi at sandia.gov
>>> 
>>> 
>>> 
>>> On Feb 24, 2011, at 1:09 PM, Kevin Van Maren wrote:
>>> 
>>>> However, I don't think you can decrease the number of running threads.
>>>> See https://bugzilla.lustre.org/show_bug.cgi?id=22417 (and also 
>>>> https://bugzilla.lustre.org/show_bug.cgi?id=22516 )
>>>> 
>>>> Kevin
>>>> 
>>>> 
>>>> Mervini, Joseph A wrote:
>>>>> Cool! Thank you Johann.
>>>>> ====
>>>>> 
>>>>> Joe Mervini
>>>>> Sandia National Laboratories
>>>>> High Performance Computing
>>>>> 505.844.6770
>>>>> jamervi at sandia.gov
>>>>> 
>>>>> 
>>>>> 
>>>>> On Feb 24, 2011, at 11:05 AM, Johann Lombardi wrote:
>>>>> 
>>>>> 
>>>>>> On Thu, Feb 24, 2011 at 10:48:32AM -0700, Mervini, Joseph A wrote:
>>>>>> 
>>>>>>> Quick question: Has runtime modification of the number of OST threads been implemented in Lustre-1.8.3?
>>>>>>> 
>>>>>> Yes, see bugzilla ticket 18688. It was landed in 1.8.1.
> 


Cheers, Andreas
--
Andreas Dilger 
Principal Engineer
Whamcloud, Inc.