As noted in patch 2, we should not require snapshotting as an obligatory feature of the external storage interface. Both because of backwards compatibility and the possibility that an external storage interface might not have this functionality.
Thoughts on this? On Thu, Jul 10, 2014 at 6:09 PM, Dimitris Aragiorgis <[email protected]> wrote: > Mention the new snapshot script and the new exported variables > in both docs and man pages. > > Signed-off-by: Dimitris Aragiorgis <[email protected]> > --- > doc/design-shared-storage.rst | 10 ++++++++++ > man/ganeti-extstorage-interface.rst | 22 +++++++++++++++++++++- > 2 files changed, 31 insertions(+), 1 deletion(-) > > diff --git a/doc/design-shared-storage.rst b/doc/design-shared-storage.rst > index 27bbd48..c1b3c01 100644 > --- a/doc/design-shared-storage.rst > +++ b/doc/design-shared-storage.rst > @@ -185,6 +185,7 @@ An “ExtStorage provider” will have to provide the > following methods: > - Detach a disk from a given node > - SetInfo to a disk (add metadata) > - Verify its supported parameters > +- Snapshot a disk (currently used during gnt-backup export) > > The proposed ExtStorage interface borrows heavily from the OS > interface and follows a one-script-per-function approach. An ExtStorage > @@ -197,6 +198,7 @@ provider is expected to provide the following scripts: > - ``detach`` > - ``setinfo`` > - ``verify`` > +- ``snapshot`` > > All scripts will be called with no arguments and get their input via > environment variables. A common set of variables will be exported for > @@ -216,6 +218,14 @@ all commands, and some of them might have extra ones. > ``VOL_METADATA`` > A string containing metadata to be set for the volume. > This is exported only to the ``setinfo`` script. > +``VOL_CNAME`` > + The human readable name of the disk (if any). > +``VOL_SNAPSHOT_NAME`` > + The name of the volume's snapshot to be taken. > + Available only to the `snapshot` script. > +``VOL_SNAPSHOT_SIZE`` > + The size of the volume's snapshot to be taken. > + Available only to the `snapshot` script. > > All scripts except `attach` should return 0 on success and non-zero on > error, accompanied by an appropriate error message on stderr. The > diff --git a/man/ganeti-extstorage-interface.rst > b/man/ganeti-extstorage-interface.rst > index f082d83..44a1adb 100644 > --- a/man/ganeti-extstorage-interface.rst > +++ b/man/ganeti-extstorage-interface.rst > @@ -22,7 +22,7 @@ REFERENCE > --------- > > There are eight required files: *create*, *attach*, *detach*, *remove*, > -*grow*, *setinfo*, *verify* (executables) and *parameters.list* > +*grow*, *setinfo*, *verify*, *snapshot* (executables) and > *parameters.list* > (text file). > > Common environment > @@ -69,6 +69,12 @@ VOL_CNAME > VOL_UUID > The uuid of the Disk config object. > > +VOL_SNAPSHOT_NAME > + The name of the volume's snapshot. > + > +VOL_SNAPSHOT_SIZE > + The size of the volume's size > + > EXECUTABLE SCRIPTS > ------------------ > > @@ -200,6 +206,20 @@ for future use and consistency with > gnt-os-interface's verify script. > > The script should return ``0`` on success. > > +snapshot > +~~~~~~~~ > + > +The *snapshot* script is used to take a snapshot of the given volume. > + > +The ``VOL_SNAPSHOT_NAME`` and ``VOL_SNAPSHOT_SIZE`` variables contain > +the name and size of the snapshot that is about to be taken. > + > +Currently this operation is used only during gnt-backup export and > +Ganeti sets those values to ``VOL_NAME.snap`` and ``VOL_SIZE`` > +respectively (see above). > + > +The script returns ``0`` on success. > + > TEXT FILES > ---------- > > -- > 1.7.10.4 > >
