Re: Desktop Filesystem Benchmarks in 2.6.3

From: Hans Reiser
Date: Tue Mar 02 2004 - 02:24:58 EST


Are you sure your benchmark is large enough to not fit into memory, particularly the first stages of it? It looks like not. reiser4 is much faster on tasks like untarring enough files to not fit into ram, but (despite your words) your results seem to show us as slower unless I misread them....

Reiser4 performs best on benchmarks that use the disk drive, and we usually only run benchmarks that use the disk drive.

Hans

Peter Nelson wrote:

I recently decided to reinstall my system and at the same time try a new file system. Trying to decide what filesystem to use I found a few benchmarks but either they don't compare all available fs's, are too synthetic (copy a source tree multiple times or raw i/o), or are meant for servers/databases (like Bonnie++). The two most file system intensive tasks I do regularly are `apt-get upgrade` waiting for the packages to extract and set themselves up and messing around with the kernel so I benchmarked these. To make it more realistic I installed ccache and did two compiles, one to fill the cache and a second using the full cache.

The tests I timed (in order):
* Debootstrap to install base Debian system
* Extract the kernel source
* Run `make all` using the defconfig and an empty ccache
* Copy the entire new directory tree
* Run `make clean`
* Run `make all` again, this time using the filled ccache
* Deleting the entire directory tree

Here is summary of the results based upon what I am calling "dead" time calculated as `total time - user time`.

You should be able to script out the user time.

As you can see in the full results on my website the user time is almost identical between filesystems, so I believe this is an accurate comparison. The dead time is then normalized using ext2 as a baseline (> 1 means it took that many times longer than ext2).

FS deb tar make cp clean make2 rm total
ext2 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
ext3 1.12 2.47 0.88 1.16 0.91 0.93 3.01 1.13
jfs 1.64 2.18 1.22 1.90 1.60 1.19 12.84 1.79
reiser 1.12 1.99 1.05 1.41 0.92 1.56 1.42 1.28
reiser4 2.69 1.87 1.80 0.63 1.33 2.71 4.14 1.83
xfs 1.06 1.99 0.97 1.67 0.78 1.03 10.27 1.43

Some observations of mine
* Ext2 is still overall the fastest but I think the margin is small
enough that a journal is well worth it
* Ext3, ReiserFS, and XFS all perform similarly and almost up to
Ext2 except:
o XFS takes an abnormally long time to do a large rm even
though it is very fast at a kernel `make clean`
o ReiserFS is significantly slower at the second make (from
ccache)
* JFS is fairly slow overall
* Reiser4 is exceptionally fast at synthetic benchmarks like copying
the system and untaring, but is very slow at the real-world
debootstrap and kernel compiles.
* Though I didn't benchmark it, ReiserFS sometimes takes a second or
two to mount and Reiser4 sometimes takes a second or two to unmount
while all other filesystem's are instantaneous.

Originally I had planned on using Reiser4 because of the glowing reviews they give themselves but I'm simply not seeing it. It might be that my Reiser4 is somehow broken but I don't think so. Based on these results I personally am now going with XFS as it's faster than ReiserFS in the real-world benchmarks and my current Ext3 partition's performance is getting worse and worse.

Full benchmark results, system information, and the script I used to run these tests are available from my website here:
<http://avatar.res.cmu.edu/news/pages/Projects/2.6FileSystemBenchmarks>

Feel free to comment, suggest improvements to my script, or run the test yourself.
-Peter Nelson




--
Hans


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