Hi! MORITA Kazutaka <[email protected]> writes:
> Even read-only access is not allowed while another qemu is doing > write access. However, there is no problem about your patch, I guess. > > It is because Sheepdog allow us to clone images only from > snapshot images. It means a backing image is always read-only. > If users specify writable Sheepdog VDI as a backing image, > qemu-img returns error. What about the case of (for example) a qcow2 file backed by a Sheepdog image? Is that also restricted to be a snapshot image (and therefore safe) or is there a potential problem there? > Therefore, If crashed qemu can be detected by a local cluster daemon, > we can monitor VMs properly. Yes, I agree. This is the sort of thing I was suggesting with my 'heartbeat' idea. It could also be done with (for example) a fcntl lock, or an open pipe, or an open stream connection: anything that is guaranteed to go away if the qemu process goes away. Best wishes, Chris. -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
