[sheepdog] [PATCH 4/4] dog: make repairing vdi optional

[Liu Yuan]

On Fri, Aug 23, 2013 at 01:03:32AM +0900, MORITA Kazutaka wrote:
> At Thu, 22 Aug 2013 22:45:43 +0800,
> Liu Yuan wrote:
> > 
> > Actually I think users should not know any options at all. Anyone tries to run
> > vdi check, is just to check the health of the targeted vdi.
> 
> I agree to this, but...
> 
> > 
> > >  - It's difficult to maintain bash_completion_dog and dog.8 if we
> > >    allow the option list.
> > > 
> > > How about adding only one option "-o, --online", which filters unsafe
> > > check/repair when the vdi is in use?
> > > 
> > > E.g.
> > > 
> > > $ vdi check                   # This tries full check.
> > > $ vdi check --online          # This filters consistency check since it
> > >                               # doesn't work if the vdi is in use
> > > 
> > > $ vdi check --repair          # This tries full check and repair
> > > $ vdi check --repair --online # This does only existence check since
> > >                               # the other tests are not safe against online vdi.
> > > 
> > 
> > From the view of ordinary user, I think concept like existence, inode, consistency
> > won't make too much difference to them. If I were the user, I'd expect
> > 
> > $ vdi check # this will check the health and report the problem if any
> > $ vdi check -r # if problems reported, users can decide to repair, whatever problem is
> > 
> > That is all. For advanced users,
> > $ vdi check -o {option list}
> > or
> > $ vdi check -opt1 -opt2 -opt2 # for easier bash_completion_dog generation.
> 
> please take into account the user who are not familiar with the
> detailed option but want to check without stopping VMs.  Online health
> checking is definitely necessary and I know actual users who need it
> inside and outside my company.  SAN storages also usually support
> scheduled health checking (without stopping storage service, of
> course).
> 

can't we simply make 'vdi check' safe against online runing vm?

> IMHO, unsafe options should be filtered out by default and enabled
> only when user explicitly enable it.  In the production service, it is
> difficult to stop all the VMs only for periodic health check and
> online checking is more common.  Even if it is not acceptable, please
> consider the way to do online health check easily.
> 

I don't think my suggestion is against your target (online health check)

Thanks
Yuan