In recent domU kernels, we need to mount the filesystems with barrier=0, because the old dom0 kernels lie about their barrier support or something. Maybe barriers are really obsolete anyway though? http://lkml.indiana.edu/hypermail/linux/kernel/1105.0/02123.html http://lists.xen.org/archives/html/xen-users/2011-12/msg00017.html
I forget where I read now, about the old dom0s lying about the barrier support which is how the filesystem can become out of whack. Is that really true?
added by lsc:
So this is a problem with the 2.6.32 dom0 kernels, but not the 2.6.18-308.4.1.el5xen (CentOS-xen) dom0 kernels? if so, perhaps we should upgrade everything to the centos-xen kernels?
We've also had the problem on hamper, which is running 126.96.36.199-xen. I will also try to test this on the centos dom0 kernel. --Nick 22:29, 29 May 2012 (EDT)