From: Christian Kujau Subject: Re: [Jfs-discussion] benchmark results Date: Thu, 24 Dec 2009 17:52:34 -0800 (PST) Message-ID: References: <19251.26403.762180.228181@tree.ty.sabi.co.uk> <20091224212756.GM21594@thunk.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Peter Grandi , xfs@oss.sgi.com, reiserfs-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, jfs-discussion@lists.sourceforge.net, ext-users , linux-nilfs@vger.kernel.org To: tytso@mit.edu Return-path: In-Reply-To: <20091224212756.GM21594@thunk.org> Sender: reiserfs-devel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, 24 Dec 2009 at 16:27, tytso@mit.edu wrote: > If you don't do a "sync" after the tar, then in most cases you will be > measuring the memory bandwidth, because data won't have been written Well, I do "sync" after each operation, so the data should be on disk, but that doesn't mean it'll clear the filesystem buffers - but this doesn't happen that often in the real world too. Also, all filesystem were tested equally (I hope), yet some filesystem perform better than another - even if all the content copied/tar'ed/removed would perfectly well fit into the machines RAM. > Another good example of well done file system benchmarks can be found > at http://btrfs.boxacle.net Thanks, I'll have a look at it and perhaps even integrate it in the wrapper script. > benchmarks for a living. Note that JFS and XFS come off much better > on a number of the tests Indeed, I was surpised to see JFS perform that good and XFS of course is one of the best too - I just wanted to point out that both of them are strangely slow at times (removing or creating many files) - not what I expected. > --- and that there is a *large* number amount > of variation when you look at different simulated workloads and with a > varying number of threads writing to the file system at the same time. True, the TODO list in the script ("different benchmark options") is in there for a reason :-) Christian. -- BOFH excuse #291: Due to the CDA, we no longer have a root account.