On Tue, May 14, 2013 at 4:40 AM, Stefan Hajnoczi <stefa...@redhat.com>wrote:
> QEMU is accumulating many different approaches to snapshots and > mirroring. They all have their pros and cons so it's not possible to > support only one approach for all use cases. > > The suggested approach is writing a BlockDriver which mirrors I/O to two > BlockDriverStates. There has been discussion around breaking > BlockDriver into smaller interfaces, including a BlockFilter for > intercepting I/O, but this has not been implemented. blkverify is an > example of a BlockDriver that manages two child BlockDriverStates and > may be a good starting point. > BlockFilter sounds interesting. The main reason I proposed 'block-trace' is because that is almost identical to what I currently have implemented with the tracing framework---I just didn't have a nice QMP command. -- Wolf
