Um, I looked again and discovered cachefilesd-0.9-1. Installing that solved the problem related to the dump, so never mind that. Sorry I missed that the first time. I'm still interested in insight as to the performance overhead. Thanks, John On Fri, Jan 2, 2009 at 10:44 AM, John Groves <John@xxxxxxxxxx> wrote: > David, > > This is related to the lustre integration that I've done. It is necessary > to summarize results as expediently as possible, which we hope justify > continuation of this work. > > To that end, although I had a lot of stability problems with the very early > fscache code in EL5 kernels, I was able to come up with a testable > configuration that demonstrates that reading from fscache is faster in > appropriate circumstances. However, I was using a cache disk subsystem that > can be read by (iozone / ext3) at 1GB/s, but the (iozone / lustre / fscache > /ext3 / fast disk) read performance was just under half that. In the old > fscache code, (iozone / Lustre / fscache / ext3 / fast disk) performance = > 0.45 (iozone / ext3 / fast disk). > > Bringing Lustre up to modern kernels is a separate piece of work, and it's > just not ready yet. For analysis purposes, we decided to test the (iozone / > nfs / fscache /ext3 / fast disk) performance on the very latest fscache code > - if the latest code incurs less performance degradation, that would support > the assertion that when Lustre is moved to late-model kernels (and therefore > late model fscache code) we'll get a [hopefully large] performance gain. > > First, do you have any performance data that might shed light on this? I > would be a bit surprised if you've tested with disk that's this fast... > > Secondly, I've built the GIT kernel with your nfs+fscache-42 patches > applied (all went in cleanly). I'm running this kernel on an otherwise > clean Fedora 10 system. fscache and cachefiles modules load cleanly, but I > can't get cachefilesd to run. If I "yum install cachefilesd", I get version > 0.7-5, and it complains that /proc/fs/cachefiles is missing. If I build > cachefilesd-0.9, I a kernel BUG. The relevant lines from /var/log/messages > are attached. > > Am I using the wrong version of cachefilesd? Is it clear what I'm doing > wrong? > > Thanks, > John Groves > > > -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cachefs
