On Sun, Sep 23, 2012 at 10:37:09AM +0800, Dave Young wrote: > For the serial number decreasing issue, I think there's only these two ways to > select, there's no ideal way to resolve this issue. > My use case for this is for the kdump kernel to find proper disks, > after 1st kernel crashing 2nd kernel need find right disk to dump vmcore. > In this case v1 and v2 aproaches are both find to me. > > From my point of view, patch v1 is better though, I think unpluging 100000 is > not a sane use case. It's not likely to happen.
I'm not sure auto-assigning serial numbers is a good idea. The guest can use the serial number in /etc/fstab or other places where it expects the serial number to be persistent. Your patch does not provide persistent serial numbers, so a change to the QEMU invocation could result in different serial numbers. The guest will get confused or perhaps refuse to boot. I'd prefer if we don't expose a temporary serial number at all in order to avoid issues like this. Stefan