On Jun 29, 2017, at 5:58 PM, John Bent <John.Bent(a)seagategov.com> wrote:
> On Jun 29, 2017, at 1:52 PM, Andreas Dilger
<adilger(a)dilger.ca> wrote:
>
>> On Jun 29, 2017, at 5:47 PM, John Bent <John.Bent(a)seagategov.com> wrote:
>>
>>> On Jun 29, 2017, at 1:35 PM, Andreas Dilger <adilger(a)dilger.ca> wrote:
>>>
>>> That means the result needs to be in "files per second"
>>
>> Absolutely. It will be just a fifth iops number to combine with the other 4 IOPs
numbers (mdtest create easy/hard and mdtest stat easy/hard) using geo mean.
>>
>> Figure out the number of files created by the four produce phases: n. Then
divide that by wall-clock for the find command: w. Then the 'find' IOPs is n/w.
>>
>> My concern is that it will be so slow that people will give up and not run it.
>
> I don't see why that would be true? For Lustre at least, readdir() and stat()
are about 2x as fast as creating files.
Even if you create across 10,000 nodes and then readdir from just 1?
Hmm, good point. I was thinking about parallel stat, but it isn't orders of magnitude
slower. George mentioned the find command took 3-4 minutes, which isn't slower than
the 5-minute create phase...
Cheers, Andreas