Re: Tell fio to only lay out files

[Jens Axboe <axboe@kernel.dk>]

On 2012-05-09 22:52, Vikram Seth wrote:
> On Wed, May 2, 2012 at 5:25 AM, Georg Sch�nberger
> <gschoenberger@thomas-krenn.com> wrote:
>> Am 2012-05-02 14:15, schrieb Jens Axboe:
>>> On 05/02/2012 02:12 PM, Georg Sch�nberger wrote:
>>>> Same error after a clean compilation.
>>>> $ fio --version
>>>> fio-2.0.7-13-g3b7f
>>>> $ fio --create_only --name=test-read-4k-4G-1-jobs --directory=./tests
>>>> --rw=read --size=10M --bs=4k --numjobs=4
>>>> max value out of range: 4 (1 max)
>>>> max value out of range: 4 (1 max)
>>> Please don't top post, reply beneath what you are replying to.
>>>
>>> Parser looks confused, because you forgot to add the value for the
>>> create_only option. If you use --create_only=1 instead, it should work.
>>>
>>> I wonder why that isn't caught in the command line variant, if you put
>>> it in a job file it does catch it:
>>>
>>> axboe@nelson:/home/axboe/git/fio $ ./fio seq-null
>>> Option create_only requires an argument
>>> fio: failed parsing create_only
>>> fio: job global dropped
>>>
>>> I'll take a look at that separately.
>>>
>> That works now:
>> $ fio --create_only=1 --name=test --directory=./tests --rw=read
>> --size=10M --bs=4k --numjobs=4
>> test: (g=0): rw=read, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> ...
>> test: (g=0): rw=read, bs=4K-4K/4K-4K, ioengine=sync, iodepth=1
>> fio-2.0.7-13-g3b7f
>> Starting 4 processes
>> test: Laying out IO file(s) (1 file(s) / 10MB)
>> test: Laying out IO file(s) (1 file(s) / 10MB)
>> test: Laying out IO file(s) (1 file(s) / 10MB)
>> test: Laying out IO file(s) (1 file(s) / 10MB)
>>
>>
>> Run status group 0 (all jobs):
>> $ ls tests/
>> test.1.0  test.2.0  test.3.0  test.4.0
>>
>> Nice!
>> Thanks, Georg
>>
>> P.S.: Sorry for top posting
>>
>>
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> 
> Hi Jens,
> 
> Does this mean that if we create the files with appropriate names and
> size before starting fio, then fio will not lay them out explicitly?
> Just confirming .. this will be very useful (reduce runtime) when
> performing tests on large filesystems.

It does, yes, or you can just use this create_only option for the same
effect.

Fio uses repeatable file names, it always has.

-- 
Jens Axboe