On Sun, Dec 05, 2004 at 11:40:21AM +0100, Michael M?ller wrote:
Hi all,
I read an article in the German 'Linux Magazin' 11/04 about a
comparision of the different FS. They tested Ext2, Ext3, JFS, XFS,
ReiserFS, Reiser4 and Veritas. Detailed results can be found on
http://www.linux-magazin.de/Service/Listings/2004/11/fs_bench.
My question is: Why is the reading performance of every FS (available
for both Linux versions) under 2.6 so bad compared to 2.4? 2.6 looses
nearly 50%!
The write performance is depending on the file size sometimes slightly
higher or lower.
Can you tell me in short words what changed from 2.4 to 2.6 that
explains the difference?
I thought that every major kernel release makes things better. So what
is now so much better that is worth to loose 50% performance?
Well, it's fairly clear they messed something up here.
My guess is that they didn't set the readahead high enough for
whatever type of device they were testing on 2.6 (It looks like a Raid
array, since on 2.4 it gets about 100MB/sec, which I don't think very
many single disks can do). The readahead implementation on 2.6 is
certainly different from the one on 2.4. IO performance on 2.6 is
much, much better across the board.
My German isn't great, so I'm not going to try and read the article,
but I'd also like to know what kind of array they are using for this
test. Before we can make any conclusions, we should know what the
hardware is capable of doing.
Sonny
___
Jfs-discussion mailing list
[EMAIL PROTECTED]
http://www-124.ibm.com/developerworks/oss/mailman/listinfo/jfs-discussion
