On Tue 31-08-10 10:11:34, Tejun Heo wrote: > On 08/30/2010 10:20 PM, Jan Kara wrote: > > 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... > > $ echo 1 > /sys/block/sdX/device/delete > $ echo - - - > /sys/class/scsi_host/hostX/scan > > should do the trick. I've tested that when mounting with barrier=0 option inside KVM, this indeed does destroy the filesystem rather badly. With the barrier option, ext4 has already survived several crash cycles while running fsstress with journal_async_commit option. So the patch seems to work as expected. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
