On Wed, Apr 29, 2020 at 7:46 PM Qu Wenruo <quwenruo.btrfs@xxxxxxx> wrote: > > > > On 2020/4/30 上午3:21, Chris Murphy wrote: > > On Wed, Apr 29, 2020 at 9:45 AM Michal Soltys <msoltyspl@xxxxxxxxx> wrote: > >> > >> Short update: > >> > >> 1) turned out to not be btrfs fault in any way or form, as we recreated > >> the same issue with ext4 while manually checksumming the files; so if > >> anything, btrfs told us we have actual issues somewhere =) > > Is that related to mixing buffered write with DIO write? > > If so, maybe changing the qemu cache mode may help? I thought this would only happen if the host is Btrfs? Maybe it's a bit crazy but these days I only use Btrfs on Btrfs with cache=unsafe. I do lots of VM force quits, never see any problems. I haven't tested it, but I think unsafe is quite unsafe if the host crashes/power fails while the guest is active. Performance is much better though. -- Chris Murphy
