Le vendredi 20 juin 2008 à 11:37 -0500, Anthony Liguori a écrit : > Laurent Vivier wrote: > > Le vendredi 20 juin 2008 à 09:07 -0500, Javier Guerra a écrit : > > > >> On Fri, Jun 20, 2008 at 7:23 AM, carlopmart <[EMAIL PROTECTED]> wrote: > >> > >>> Felix Leimbach wrote: > >>> > >>>>> This is my first post to this list. I have already installed kvm-70 > >>>>> under rhel5.2. My intention is to share on disk image betwwen two > >>>>> rhel5.2 > >>>>> kvm guests. Is it possible to accomplish this in kvm like xen or vmware > >>>>> does?? How can I do?? I didn't find any reference abou this on kvm > >>>>> documentation ... > >>>>> > >> i tried this looong ago and didn't really work because there was some > >> userspace cache on each QEMU instance. but the -drive option has a > >> 'cache=off' setting that should be enough. > >> > >> in theory (i haven't tested, but Avi 'blessed' it): > >> - create a new image with qemu-img > >> - add it to the command line using -drive file=xxx,cache=off on both > >> KVM instances > >> - use a cluster filesystem! > >> > > > > RFC: > > > > Well, well, perhaps it is delusions of a sick mind but since the > > introduction of qemu-nbd I think we can develop easily something to > > share a disk between several virtual hosts: > > > > I- in a first step, we can modify qemu-nbd to accept several connections > > for one disk image, for instance: > > > > # qemu-nbd my-disk.qcow2 > > # nbd-client localhost 1024 /dev/nbd0 > > # nbd-client localhost 1024 /dev/nbd1 > > > > and start two virtual hosts: > > > > "qemu -hda v1.img -hdb /dev/nbd0" and "qemu -hda v2.img -hdb /dev/nbd1" > > > > Of course the filesystem must know how to share the access to the disk > > with others (-> "cluster filesystem") > > > > II- in a second step, we can include directly the nbd protocol in qemu > > (block-nbd.c, "-drive file=nbd:localhost:1024") to connect to the > > server. We can also add some commands to the protocol to manage lock, > > HA, "what else ?" (Hi George). > > > > http://hg.codemonkey.ws/qemu-pq/file/25ca451f2040/block-nbd.diff
You're not fun, Anthony. Perhaps, now, it should be better if you use functions defined in the (new) file "nbd.c". Laurent > Regards, > > Anthony Liguori > > > Any comments ? > > > > Cheers, > > Laurent > > > > -- ------------- [EMAIL PROTECTED] --------------- "The best way to predict the future is to invent it." - Alan Kay -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
