Re: [Qemu-devel] [RFC] block-trace Low Level Command Supporting Disk Introspection

[Paolo Bonzini]

Il 14/05/2013 10:50, Kevin Wolf ha scritto:
> Or, to translate it into our existing terminology, drive-mirror
> implements a passive mirror, you're proposing an active one (which we
> do want to have).
> 
> With an active mirror, we'll want to have another choice: The mirror can
> be synchronous (guest writes only complete after the mirrored write has
> completed) or asynchronous (completion is based only on the original
> image). It should be easy enough to support both once an active mirror
> exists.

Right, I'm waiting for Stefan's block-backup to give me the "right"
hooks for the active mirror.

The bulk phase will always be passive, but an active-asynchronous mirror
has some interesting properties and it makes sense to implement it.

Paolo