Re: EXT4 RAID read performance

From: wbrana
Date: Sat Sep 26 2009 - 10:27:59 EST


On Sun, Sep 20, 2009 at 1:18 AM, Theodore Tso <tytso@xxxxxxx> wrote:
> You didn't say which version of the kernel you are using, which could
> be important when asking these sorts of questions about potential
> performance problems.
>
2.6.31

>
> Now, there are some workloads which compilebench might accurately
> model --- for example, tar'ing up a directory. ÂHowever, despite the
> name of the benchmark, it doesn't accurately model a kernel compile.
>

You are right. I created simple benchmark which does real compilation of kernel
with following results:

reiser3
16925 msec: tar xf /usr/src/linux.tar
119173 msec: make -j4 all

ext4
14296 msec: tar xf /usr/src/linux.tar
116692 msec: make -j4 all

btrfs
13493 msec: tar xf /usr/src/linux.tar
116015 msec: make -j4 all

MD RAID10-f2 with 256 kB chunk size was used in all cases.

Source code:
http://www.sendspace.com/file/fmikv7
It depends on Qt Core library. There are hard-coded paths.
It can delete important data if it is started without customization !!!
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