On Mon, Jul 31 2006, Jonas Maebe wrote: > > On 31 jul 2006, at 09:08, Jens Axboe wrote: > > >>Applications running on the host can count on fsync doing the > >>right thing, meaning that if they call fsync, the data *will* > >>have made it to disk. Applications running inside a guest have > >>no guarantees that their data is actually going to make it > >>anywhere when fsync returns... > > > >Then the guest OS is broken. > > The problem is that supposedly many OS'es are broken in this way. See > http://lists.apple.com/archives/darwin-dev/2005/Feb/msg00072.html
Well, as others have written here as well, then their OS are broken on "real" hardware as well. I wouldn't be adverse to a QEMU work-around, but O_SYNC is clearly not a viable alternative! We could make QEMU behave more like a real hard drive when it has aio support, "flushing" dirty cache out in a manner more closely mimicking what a drive would do instead of relying on the page cache writeout deciding to write it out. -- Jens Axboe _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel
