sysbench / fileio - Linux vs. FreeBSD

[Igor Mozolevsky]

>>>> /usr/src : zfs with compression enabled
>>>> /usr/src : 386.3MB/s

>>> Do I understand it well? It seems that zfs with compression enabled on
>>> /usr/src with 8KB block size and 16 threads performs 386.3MB/s which
>>> is about 6 times better than debian5? I am thinking about this image
>>> http://tech-blog.wooh.hu/~wooh/debian_vs_freebsd_io_16_seqwr.png
>>
>> Yes - on one run it even hit 500MB/s. I suspect, however, that the
>> benchmark isn't accurate because it won't be writing typical data.
>> Instead it's probably using a buffer that compresses very well.
>
> Hm.. My ZFS tests showed me the same results. With compression it's
> pretty fast.

That's hardly a surprise - you take the source code, compress it into
virtual non-existence leaving hardly anything to be written to the
disk... Obviously if compression speed >> IO speed and the result of
the compression is a significant reduction in size, you have a massive
gain in writing that data to the disk.


--
Igor