[lustre-discuss] Why reads are slower than writes in lustre

[Colin Faber]

The amount of data you're testing is far too small. Try upping it 10x so
you have a longer run time and you achieve a more reasonable average.

On Tue, Sep 28, 2021 at 6:02 PM Nagmat Nazarov <nagmat at nevada.unr.edu>
wrote:

> Dear Engineers,
>
> I have started working on a lustre file system. I have done a couple of
> experiments so far:
> On the first experiment I am writing 100 files each 10MB and the batch
> size is 4K. I got *704MB/s* bandwidth.
>
> On the second experiment I am (writing 10 files each 10MB and reading 1 10
> MB file back) for 10 times.  Here also the average write bandwidth is
> *697MB/s* while  read average bandwidth is *380MB/s* which is very weird
> I guess?
>
> Experiment files are on : *https://github.com/nagmat1/lustre_installation-experiment
> <https://github.com/nagmat1/lustre_installation-experiment>*
> I am using FIO as workload generator : *https://github.com/axboe/fio
> <https://github.com/axboe/fio> *
>
> My question is, generally on ext4 file systems read average bandwidth is
> faster that write average bandwidth, why is it *2 times slower *on lustre
> file system. My ethernet speed is *10000Mb/s.*
>
> Kind regards
> Nagmat Nazarov
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>
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