On Sat, Dec 11, 2010 at 9:16 PM, Jon Nelson <jnelson@xxxxxxxxxxx> wrote: > On Sat, Dec 11, 2010 at 7:40 PM, Ted Ts'o <tytso@xxxxxxx> wrote: >> Yes, indeed. ÂIs this in the virtualized environment or on real >> hardware at this point? ÂAnd how many CPU's do you have configured in >> your virtualized environment, and how memory memory? ÂIs having a >> certain number of CPU's critical for reproducing the problem? ÂIs >> constricting the amount of memory important? > > Originally, I observed the behavior on really real hardware. > > Since then, I have been able to reproduce it in VirtualBox and > qemu-kvm, with openSUSE 11.3 and KUbuntu. All of the more recent tests > have been with qemu-kvm. > > I have one CPU configured in the environment, 512MB of memory. > I have not done any memory-constriction tests whatsoever. > >> It'll be a lot easier if I can reproduce it locally, which is why I'm >> asking all of these questions. > > On Sat, Dec 11, 2010 at 8:34 PM, Ted Ts'o <tytso@xxxxxxx> wrote: >> One experiment --- can you try this with the file system mounted with >> data=writeback, and see if the problem reproduces in that journalling >> mode? > > That test is running now, first with encryption. I will report if it > shows problems. If it does, I will wait until I have been able to see > that a few times, and move to a no-encryption test. Typically, I have > to run quite a few more iterations of that test before problems show > up (if they will at all). > >> I want to rule out (if possible) journal_submit_inode_data_buffers() >> racing with mpage_da_submit_io(). ÂI don't think that's the issue, but >> I'd prefer to do the experiment to make sure. ÂSo if you can use a >> kernel and system configuration which triggers the problem, and then >> try changing the mount options to include data=writeback, and then >> rerun the test, and let me know if the problem still reproduces, I'd >> be really grateful. Using 2.6.37-rc5 and data=writeback,noatime and LUKS encryption I hit the problem 71 times out of 173. -- Jon -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
