Am 21.06.2010 17:34, schrieb Anthony Liguori: > On 06/21/2010 09:01 AM, Kevin Wolf wrote: >> >> No, what I'm saying is that even in your model >> >> -blockdev format=qcow2,file=image.qcow2,id=blk1 >> >> becomes qcow2 -> file automatically, whereas >> >> -blockdev format=vvfat,file=/tmp/dir/,id=blk1 >> >> doesn't become vvfat -> file, but stays just vvfat. >> > > I should say, that -blockdev format= vs. -blockdev transport= is > definitely at a place where I don't care that much. > > The things that I think are most important are: > > 1) That we have structured options that map well to config file without > trickery to do nesting > 2) That we don't automagically pass options through from the first layer > down to subsequent layers
Does this mean that you need to specify the protocol explicitly for any non-trivial case? So if you want to use just default for everything you can use -blockdev id=foo,format=qcow2,file=foo.qcow2 and it will be turned into something sensible automagically (namely adding a file blockdev underneath and passing the file parameter to that one), but if you want to change an option, you need to specify both? -blockdev id=foo,format=qcow2,parent=foo_file -blockdev id=foo_file,format=file,file=foo.qcow2,cache=off What about read-only? Is it something that must be specified for each single node in the chain to actually get the right semantics? Kevin
