On Mon 30-08-10 15:56:43, Jeff Moyer wrote: > Jan Kara <jack@xxxxxxx> writes: > > > An update: I've set up an ext4 barrier testing in KVM - run fsstress, > > kill KVM at some random moment and check that the filesystem is consistent > > (kvm is run in cache=writeback mode to simulate disk cache). About 70 runs > > But doesn't your "disk cache" survive the "power cycle" of your guest? Yes, you're right. Thinking about it now the test setup was wrong because it didn't refuse writes to the VM's data partition after the moment I killed KVM. Thanks for catching this. I will probably have to use the fault injection on the host to disallow writing the device at a certain moment. Or does somebody have a better option? My setup is that I have a dedicated partition / drive for a filesystem which is written to from a guest kernel running under KVM. I have set it up using virtio driver with cache=writeback so that the host caches the writes in a similar way disk caches them. At some point I just kill the qemu-kvm process and at that point I'd like to also throw away data cached by the host... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
