Tomasz Chmielewski wrote: > Anthony Liguori schrieb: > > (...) > >> I don't believe a PV block driver is actually necessary. Disk >> devices are actually quite slow (unless you have a large array). >> With a few small changes (bump MMU cache up to 1024 and actually >> enable the aio subsystem), SCSI emulation does as well as Xen's PV >> block driver (about 210 mb/sec whereas native is around 250 mb/sec). >> There's a lot of room to optimize the SCSI emulation too since there >> are a number of copies in that path. >> >> The SCSI emulation is a lot like what one would design in a PV >> driver. It supports multiple outstanding requests and doesn't >> require a whole lot of exits to submit a request (it uses scripts). > > How does one enable SCSI emulation?
Right now, you have to modify the source code :-/ > "qemu-system-x86_64 -h" gives no hints about SCSI (at least in > KVM-18); similarly, I didn't find anything in the archive or in the wiki. > > > Certainly, there is a kvm-18/qemu/hw/scsi-disk.c file, so it's like > the feature is there... > > Is it possible to boot a guest from a "SCSI-emulated" device? Not yet. There is work being done on an option ROM to allow SCSI boot support though. Regards, Anthony Liguori ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/kvm-devel
