Re: [Qemu-devel] [PATCH v1] hmp: 'info snapshots' not showing the id

[seeteena]

On 01/02/2018 01:54 PM, Markus Armbruster wrote:
> seeteena <address@hidden> writes:
>
> > On 12/22/2017 01:07 PM, Markus Armbruster wrote:
> > > Eric Blake <address@hidden> writes:
> > >
> > > > On 12/19/2017 08:20 AM, Max Reitz wrote:
> > > >
> > > > > So there are three things:
> > > > >
> > > > > (1) We probably should not allow snapshot names that could be IDs.
> > > > > Easiest way to solve this: Names have to start with a non-digit.
> > > > Yes, that would be a nice change.  It is not strictly backwards
> > > > compatible (so we'd still have to cope with images that didn't follow
> > > > the rule, whether created by older qemu or by non-qemu implementations
> > > > of qcow2), but would alleviate a lot of confusion.
> > > I recommend to restrict ID strings to letters, digits, '-', '.', '_',
> > > starting with a letter.  Use id_wellformed() to check.
> > char *id_generate(IdSubSystems id) autogenates ID in the format eg-
> > "#block146" with starting with '#' always.
> > restricting ID strings to use id_wellformed() means we need to force
> > ID to start with letter.
> >
> > #define ID_SPECIAL_CHAR '#' needs to change to (some letter)
> > #define ID_SPECIAL_CHAR 'A'
> Ensuring auto-generated IDs cannot clash with IDs chosen by the user is
> a good idea.  We generally fail to do that in QEMU.
>
> An obvious way to do it is to require the user's IDs to start with a
> letter, and auto-generated IDs to start with another suitable character.
> In theory, starting with '#' is problematic, because it needs to be
> quoted in shell at the beginning of words.  Only matters if
> auto-generated IDs make sense in command lines, which I guess they
> currently don't.  I'd prefer a 'shell-safe' character all the same.

I was using loaned system from other team for recreate and it appears 
there is some issue in that system and I am not able to recreate the 
issue now.


QEMU 2.11.50 monitor - type 'help' for more information
(qemu) savevm 0
Error while creating snapshot on 'rootdisk'
(qemu) savevm 0
Error while creating snapshot on 'rootdisk'
(qemu) savevm 0
Error while creating snapshot on 'rootdisk'
(qemu) savevm 1
Error while creating snapshot on 'rootdisk'
(qemu)

> > > If backward compatibility is an issue, deprecate offending IDs (with a
> > > suitable warning), and kill them off after the customary grace period.
> > >
> > > IDs embedded in image files and such you may have to keep working
> > > somehow indefinitely.