On Tue, Oct 01, 2013 at 03:41:04PM +0200, Stefan Hajnoczi wrote: > On Wed, Sep 25, 2013 at 05:02:45PM -0400, Jeff Cody wrote: > > > > This patch series contains the initial VHDX log parsing, replay, > > write support, and image creation. > > > > === v6 changes === > > https://github.com/codyprime/qemu-kvm-jtc/tree/vhdx-write-v6-upstream > > > > Rebased to latest qemu/master: > > > > Patch 16/20: .bdrv_create() propagates Error, and bdrv_unref() used > > instead of bdrv_delete(). > > > > Patch 17 & 18 are already included in another series: > > [PATCH v3 0/3] qemu-iotests with sample images, vhdx test, cleanup > > > > They are included here to provide a base for patches 19 & 20. If the above > > series is applied before this series, then patches 17 and 18 can be ignored. > > > > Patch 19/20: In qemu-io tests _make_test_img(), filter out vhdx-specific > > options for .bdrv_create(). > > > > Patch 20/20: Add VHDX write test case to 064. > > Sorry for the late review. Feel free to poke Kevin or me if we're being > slow - the squeaky wheel gets the grease. > > I left comments on a couple of the core journal and write patches. It > looks pretty good overall. > > How is the journal code tested? IIUC the sample image file does not > have a dirty journal. Please try to include an image that Hyper-V > created with a dirty journal so we can be sure flushing the journal > works.
Getting Hyper-V generated files with journals is a bit challenging. The methodology I've been using is a Linux guest under Hyper-V, generating a lot of guest i/o that will cause metadata updates (e.g. dd if=/dev/sda of=/dev/sdb, etc..). While this is going on, I hit the reset button on the server. Kinda messy, but it works, if not very deterministically. I initially tried just killing the process, but I was unable to do that and obtain a dirty log. The problems with the images I've created in this manner is they are much too large to put in our repo. However, if I write repetitive data, that should allow the image to be compressed adequately... I'll give that a try. I've tested the other direction too (which is much easier) - create a VHDX image under QEMU, leave a dirty journal, and then open the image file with the dirty journal under Hyper-V. It replayed it, and the sha1sum of the affected file inside the image was correct after replay.
