[sheepdog] [PATCH] collie: add command 'collie vdi reset' to reset a cloned VDI

[MORITA Kazutaka]

At Wed, 29 Aug 2012 15:18:12 +0800,
levin li wrote:
> 
> On 2012年08月29日 15:08, MORITA Kazutaka wrote:
> > At Wed, 29 Aug 2012 13:57:57 +0800,
> > levin li wrote:
> >>
> >> From: levin li <xingke.lwp at taobao.com>
> >>
> >> With this command, we can reset a cloned VDI to its initial state as
> >> it's just cloned from a snapshot, the usage is simple:
> >>
> >> $ collie vdi reset cloned_vdi_name
> >>
> >> Signed-off-by: levin li <xingke.lwp at taobao.com>
> >> ---
> >>  collie/collie.h |    1 +
> >>  collie/common.c |   35 ++++++++++++++++++++++++++++++
> >>  collie/vdi.c    |   63 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  3 files changed, 99 insertions(+), 0 deletions(-)
> > 
> > What is the use case of this command?  Isn't it enough to delete the
> > vdi and recreate it from snapshots?
> > 
> > Thanks,
> > 
> > Kazutaka
> > 
> 
> It does the same thing as we delete the VDI first and recreate it, but faster than
> the combination of the two commands, we don't need to call lookup_vdi too many times,
> and many operations of the VDI deletion can be saved with this command if we only
> want to reset the VDI.

How about generalizing the command to a rollback command like as
follows?

 $ collie vdi rollback -s [snapshot tag/id]

I guess it will help much more people than just reseting a clone image
to the initial state.

Thanks,

Kazutaka