Re: [Xen-devel] [RFC v3] domain snapshot documents

[David kiarie <davidkiarie4@xxxxxxxxx>]

Looks Okay now.

On Mon, May 19, 2014 at 6:45 AM, Bamvor Jian Zhang <bjzhang@xxxxxxxx> wrote:
> Hi, David
>> On Fri, May 16, 2014 at 6:00 PM, Bamvor Jian Zhang <bjzhang@xxxxxxxx> wrote:
>>
>> > Hi, david
>> >
>> > > On Thu, May 15, 2014 at 4:58 PM, Bamvor Jian Zhang <bjzhang@xxxxxxxx>
>> > wrote:
>> > >
>> > > > Hi,
>> > > >
>> > > > here is the third version about domain snapshot documents, the second
>> > > > version
>> > > > and the first version is here[1][2].
>> > ...
>> > > > 2, new functions
>> > > > there is no common api like libxl_snapshot_xxx. the reason is that
>> > > > different
>> > > > toolstack may need to different event handling machanism(synchronize or
>> > > > asynchronize). and obviously, domain snapshot create need async
>> > handler.
>> > > > so i
>> > > > decide to only provide the sub api for xl and other toolstack(e.g.
>> > > > libvirt).
>> > > > it make eailer for toolstack to handle the event by themselves.
>> > > >
>> > > > 1), in libxl/libxl.h
>> > > > the implementation will be located in libxl_snapshot.c
>> > > > /* disk snapshot api
>> > > >  * support create for external and internal disks, support delete for
>> > > > internal
>> > > >  * snapshot of disks.
>> > > >  */
>> > > > /* create disk snapshot according to the device name in snapshot
>> > array. nb
>> > > > is
>> > > >  * the number of snapshot array.
>> > > >  * use the qmp transaction to ensure all snapshot of disk is coherence.
>> > > >  */
>> > > > int libxl_disk_snapshot_create(libxl_ctx *ctx, int domid,
>> > > >                                libxl_disk_snapshot *snapshot, int nb,
>> > > >                                const libxl_asyncop_how *ao_how);
>> > > > /* delete number of nb disk snapshot describe in snapshot array
>> > > >  */
>> > > > int libxl_disk_snapshot_delete(libxl_ctx *ctx, int domid,
>> > > >                                libxl_disk_snapshot *snapshot, int nb);
>> >
>> Are this the only two functions you are exposing?I mean the API?or am I
>> getting something wrong?
>>
> there are functions libxl_qmp_loadvm, libxl_qmp_savevm which is called by
> domain internal snapshot create/revert. currently, they are internal 
> functions.
> (libxl_intenal.h). but i should expose them, e.g. look like:
> int libxl_loadvm(libxl_ctx *ctx, int domid, libxl_domain_snapshot *snapshot,
>                  const libxl_asyncop_how *ao_how);
> int libxl_savevm(libxl_ctx *ctx, int domid, libxl_domain_snapshot *snapshot,
>                  const libxl_asyncop_how *ao_how);
>
> sorry for confuse.
>
> regards
>
> bamvor
>
>> > > >
>> > > I think we also need revert libxl_disk_snapshot_revert() here.
>> > there are two methods for revert disk snapshot state in qemu: call
>> > "loadvm" hmp
>> > and "qemu-img snapshot -a". and i will call loadvm for reverting the qemu
>> > state
>> > and disk state in libxl_snapshot_create.
>> > user could revert the dedicate disk snapshot with qemu-img when domain is
>> > not
>> > running.it seems not a good idea wrap the qemu-img command in libxl.
>> >
>> > regards
>> >
>> > bamvor
>> >
>
>
>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel