On 05/26/2010 03:48 PM, Anthony Liguori wrote:
We might get 100 bug reports about this "regression" but they concern much less than 1 bug report of image corruption because of power failure/host crash. A reputation of being unsafe is very difficult to get rid of and is something that I hear concerns about frequently.
True, but how many people will use cache=volatile? Nobody is going to make it the default. If a blog post appears "hey look cache=volatile will speedup your virtual machine", and gets so much momentum that people start using it and lose data because of it (which is highly hypothetical and unlikely), QEMU developers are not the ones to be blamed.
I'm not suggesting that the compile option should be disabled by default upstream. But the option should be there for distributions because I hope that any enterprise distro disables it.
Actually it's perfectly possible that they will _enable_ it if a configure option is required to enable cache=volatile. RHEL for example doesn't support at all running qemu directly, only via libvirt. If libvirt doesn't pass cache=volatile to qemu, they're safe.
(Well, virt-install uses libvirt, so it couldn't use cache=volatile either, so I admit it's not a great example).
Paolo
