On Thu, 2 Nov 2023 at 10:43, Kevin Wolf <kw...@redhat.com> wrote: > > Am 01.11.2023 um 12:21 hat Peter Maydell geschrieben: > > On Tue, 31 Oct 2023 at 18:45, Kevin Wolf <kw...@redhat.com> wrote: > > > Am 16.10.2023 um 13:58 hat Michael Tokarev geschrieben: > > > > Almost everyone mentions -blockdev as a replacement for -drive. > > > > > > More specifically for -drive if=none. I honestly don't know many common > > > use cases for that one. > > > > One use case for it is "create a drive with a qcow2 backend to use > > for -snapshot snapshots, but don't plug it into anything". See > > https://translatedcode.wordpress.com/2015/07/06/tricks-for-debugging-qemu-savevm-snapshots/ > > I dunno whether that counts as "common", though :-) > > Ok, I was already wondering what good -snapshot was for an image that > isn't even used, but what the article describes is actually not using > -snapshot, but internal snapshots with savevm/loadvm, i.e. using the > image to store the VM state. > > This actually makes a lot of sense for if=none, as one of the few cases > where "none" accurately tells what device it will be used with.
Whoops, have I got the terminology wrong again? To me these are "snapshots" (they do store the whole VM state including the current state of the disk, and "qemu-img info" lists them as "snapshots"), whereas I never use the '-snapshot' option, so I never remember that we have two different things here. Sorry for introducing confusion :-( thanks -- PMM