[libvirt] [PATCH 0/4] Preparation for external live snapshot

[Michal Privoznik]

On 18.08.2012 04:08, Eric Blake wrote:
> I've determined that it is possible to mix migration to file
> with disk snapshots on existing qemu 1.1 in such a way to
> take a live system checkpoint snapshot of a system without
> the downtime of either 'virsh snapshot-create' or 'virsh save';
> without the loss in disk state of 'virsh save'; and without
> the fsck penalties of 'virsh snapshot-create --disk-only';
> basically by combining the best of those three approaches.
> 
> I'm also quite tired of 'virsh snapshot-create --disk-only'
> failing for an offline domain, and have upcoming patches to
> drive qemu-img to do that for an offline image.
> 
> Unfortunately, qemu 1.2 missed out on adding the 'drive-mirror'
> or 'block-commit' commands, so I still can't do quite everything
> I want with snapshots (in particular, I can't preserve the
> original filename; although you can do a snapshot/blockpull/snapshot
> to get back to the original filename with twice the work).  But
> I think this series still leaves room for future enhancements
> as future qemu provides the means.
> 
> Although I'm still in the middle of polishing the src/qemu patches,
> I'd at least like to post this series of prep-work to document
> how I plan to expose it all, and to make sure my design
> decisions are on track.  The first three can be applied now,
> the fourth should probably not be applied until I actually have
> later patches using the new XML, hopefully still in time for 0.10.0.
> 
> Eric Blake (4):
>   snapshot: make virDomainSnapshotObjList opaque
>   snapshot: split snapshot conf code into own file
>   snapshot: rename an enum
>   snapshot: new XML for external system checkpoint
> 
>  docs/formatsnapshot.html.in                        |   11 +
>  docs/schemas/domainsnapshot.rng                    |   23 +
>  po/POTFILES.in                                     |    1 +
>  src/Makefile.am                                    |    3 +-
>  src/conf/domain_conf.c                             |  933 +-----------------
>  src/conf/domain_conf.h                             |  143 +--
>  src/conf/snapshot_conf.c                           | 1021 ++++++++++++++++++++
>  src/conf/snapshot_conf.h                           |  160 +++
>  src/esx/esx_driver.c                               |    1 +
>  src/libvirt_private.syms                           |    5 +-
>  src/qemu/qemu_command.c                            |    1 +
>  src/qemu/qemu_domain.c                             |    7 +-
>  src/qemu/qemu_domain.h                             |    3 +-
>  src/qemu/qemu_driver.c                             |   69 +-
>  src/qemu/qemu_migration.c                          |    2 +-
>  src/vbox/vbox_tmpl.c                               |    1 +
>  tests/domainsnapshotxml2xmlin/external_vm.xml      |   10 +
>  tests/domainsnapshotxml2xmlin/noparent.xml         |    9 +
>  tests/domainsnapshotxml2xmlout/all_parameters.xml  |    1 +
>  tests/domainsnapshotxml2xmlout/disk_snapshot.xml   |    1 +
>  tests/domainsnapshotxml2xmlout/external_vm.xml     |   43 +
>  tests/domainsnapshotxml2xmlout/full_domain.xml     |    1 +
>  tests/domainsnapshotxml2xmlout/metadata.xml        |    1 +
>  tests/domainsnapshotxml2xmlout/noparent.xml        |    1 +
>  .../noparent_nodescription.xml                     |    1 +
>  .../noparent_nodescription_noactive.xml            |    1 +
>  tests/domainsnapshotxml2xmltest.c                  |    1 +
>  27 files changed, 1365 insertions(+), 1089 deletions(-)
>  create mode 100644 src/conf/snapshot_conf.c
>  create mode 100644 src/conf/snapshot_conf.h
>  create mode 100644 tests/domainsnapshotxml2xmlin/external_vm.xml
>  create mode 100644 tests/domainsnapshotxml2xmlin/noparent.xml
>  create mode 100644 tests/domainsnapshotxml2xmlout/external_vm.xml
> 

Eric,

I could apply the first patch (however using 3-way merge) but cannot the
second. Can you please (rebase? and) resend? Or is this intended to be
applied on the top of another patchset:

Applying: snapshot: split snapshot conf code into own file
fatal: sha1 information is lacking or useless (src/conf/domain_conf.c).
Repository lacks necessary blobs to fall back on 3-way merge.
Cannot fall back to three-way merge.
Patch failed at 0001 snapshot: split snapshot conf code into own file
When you have resolved this problem run "git am --resolved".
If you would prefer to skip this patch, instead run "git am --skip".
To restore the original branch and stop patching run "git am --abort".

Michal