On Mon, Jul 12, 2010 at 03:34:44PM +0200, Giangiacomo Mariotti wrote: > On Mon, Jul 12, 2010 at 9:09 AM, Michael Tokarev <mjt@xxxxxxxxxx> wrote: > > > > This looks quite similar to a problem with ext4 and O_SYNC which I > > reported earlier but no one cared to answer (or read?) - there: > > http://permalink.gmane.org/gmane.linux.file-systems/42758 > > (sent to qemu-devel and linux-fsdevel lists - Cc'd too). You can > > try a few other options, esp. cache=none and re-writing some guest > > files to verify. > > > > /mjt > > > Either way, changing to cache=none I suspect wouldn't tell me much, > because if it's as slow as before, it's still unusable and if instead > it's even slower, well it'd be even more unusable, so I wouldn't be > able to tell the difference. What I can say for certain is that with > the exact same virtual hd file, same options, same system, but on an > ext3 fs there's no problem at all, on a Btrfs is not just slower, it > takes ages. > O_DIRECT support was just introduced recently, please try on the latest kernel with the normal settings (which IIRC uses O_DIRECT), that should make things suck alot less. Thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
