On 10/16/2009 07:45 PM, Antoine Martin wrote:
Hi, Is there an easy way that I have missed to share a virtual disk read-only between many guests whilst still having the ability to update it occasionally from the host?
That's very fragile, since the guest won't expect the disk to change under its feet. Expect oopses.
I was hoping I could use a shared image file, and occasionally replace it with an updated version (move old copy to disk_image.bak, copy new image to disk_image), then the guests could umount/mount the drive and get access to the new disk image. Unfortunately qemu opens the virtual disk as soon as the guest boots, so the file descriptor still points to the old image. Note: I do not want to use the qemu monitor from the host as I want the guests to be in charge of when/if they get the new disk image.
I suggest using a monitor, and have the host and guest coordinate the change (guest unmounts, host modifies, guest mounts).
Alternatively, export the disk from the host using nfs. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
