I'm not sure on a release for when I'll implement snapshot functionality. Maybe 4.4.
On Thu, Sep 19, 2013 at 6:16 AM, SuichII, Christopher < chris.su...@netapp.com> wrote: > John - any chance we can get your input on the original topic. Mikes > comment was a kind of unrelated (but a completely valid topic that I'd like > to be a part of discussing anyway!). > > Mike - are you planning on implementing the snapshotting methods of the > storage subsystem API anytime in the near future? > > Kelvin or Darren, do you have thoughts on how thoughts on how this will > work regarding the user experience? As a user, I would be quite annoyed if > I had to back up all of my vms one at a a time. I guess I'm still not sure > I understand the opposition to allowing users to perform an action on more > than one object at a time. I know that is kind of a foreign concept in > CloudStack right now, as the UI doesn't support it, but that is something I > am currently working on any (extending the UI to support this). If it is > strictly a matter of making sure the user's expectations regarding > consistency are in line with what happens, then I think that is a separate > discussion. > > Maybe others would find it useful to have an API like this exposed if they > are interacting with CloudStack directly through the APIs rather than the > UI. Imagine being a developer consuming our APIs. It certainly seems > cleaner (at least to me), to let the user call one API with a list of vms > to backup them all up instead of them requiring to loop around as many vms > as they want and having to call the same API that many times. > > To be perfectly clear, Kelvin, the benefit to propagating the ability to > backup multiple vm volumes at once to the UI is about ease of use for users > and ease of development for us - us being CS developers, CS plugin > developers and CS API consumers. > > -- > Chris Suich > chris.su...@netapp.com > NetApp Software Engineer > Data Center Platforms – Cloud Solutions > Citrix, Cisco & Red Hat > > On Sep 19, 2013, at 1:00 AM, Kelven Yang <kelven.y...@citrix.com> wrote: > > > > > > > On 9/18/13 9:10 AM, "Darren Shepherd" <darren.s.sheph...@gmail.com> > wrote: > > > >> Here's my general concern about multiple volume snapshots at once. > Giving > >> such a feature leads the user to believe that snapshotting multiple > >> volumes > >> at once will give them consistency across the volumes in the snapshot. > >> This is not true, and difficult to do with many hypervisors, and > typically > >> requires an agent in the VM. A single snapshot, as exists today, is > >> really > >> crash consistent, meaning that there is may exist unsync'd data. To do > a > >> true multi volume snapshot requires a "quiesce" functionality in the VM. > >> So you do pause I/O queues, fsync, fsync, snapshot, snapshot, unpause > I/O. > >> > >> I'm might be fine with the option of allowing multiple volumeId's to be > >> specified in the snapshot API, but it needs to be clear that those > >> snapshots may be taken sequentially and they are all independently crash > >> consistent. But, if you make that clear, then why even have the API. > >> Essentially it is the same as doing multiple snapshot API commands. > >> > >> So really I would lean towards having the multiple snapshotting > supported > >> in the driver or storage subsystem, but not exposed to the user. You > can > >> easy accomplish it by having a timed window on snapshotting. So every > 10 > >> seconds you do snapshots, if 5 requests have queued in the last 10 > >> seconds, > >> you do them all at once. This could be implemented as a framework > thing. > >> If your provider implements "SnapshotBatching" interface and that has a > >> getBatchWindowTime(), then the framework can detect that it should try > to > >> queue up some snapshot requests and send them to the driver in a batch. > >> Or > >> that could be implemented in the driver itself. > > > > It makes more sense to me that "SnapshotBatching" is made available at > > storage framework layer for similar drivers that have such batch > > capability to share. There also exists another potential intelligent > > processing - when storage subsystem layer processes independent > > volume-snapshot requests falling into the window, it can aggregate the > > requests targeting for the same VM instance into groups, this can allow > > hypervisor level drivers to take advantage of hypervisor provided VM > > snapshot wisely. > > > > So +1 for storage layer - driver interface enhancements like this, but I > > don't see much immediate benefit to propagate it into end-user API layer. > > > > -Kelven > > > > > >> I would lean toward doing > >> it in the driver and if that goes well, we look at pulling the > >> functionality into core ACS. > >> > >> Darren > >> > >> > >> On Wed, Sep 18, 2013 at 5:22 AM, SuichII, Christopher < > >> chris.su...@netapp.com> wrote: > >> > >>> I would like to raise for discussion the idea of adding a couple > methods > >>> to the Storage Subsystem API interface. Currently, takeSnapshot() and > >>> revertSnapshot() only support single VM volumes. We have a use case for > >>> snapshotting multiple VM volumes at the same time. For us, it is more > >>> efficient to snapshot them all at once rather than snapshot VM Volumes > >>> individually and this seems like a more elegant solution than queueing > >>> the > >>> requests within our plugin. > >>> > >>> Base on my investigation, this should require: > >>> -Two additional API to be invoked from the UI > >>> -Two additional methods added to the Storage Subsystem API interface > >>> -Changes in between the API level and invoking the Storage Subsystem > API > >>> implementations (I know this is broad and vague), mainly around the > >>> SnapshotManger/Impl > >>> > >>> There are a couple topics we would like discussion on: > >>> -Would this be beneficial/detrimental/neutral to other storage > >>> providers? > >>> -How should we handle the addition of new methods to the Storage > >>> Subsystem > >>> API interface? Default them to throw an UnsupportedOperationException? > >>> Default to calling the single VM volume version multiple times? > >>> -Does anyone see any issues with allowing multiple snapshots to be > taken > >>> at the same time or letting storage providers have a list of all the > >>> requested volumes to backup? > >>> > >>> Please let me know if I've missed any major topics for discussion or if > >>> anything needs clarification. > >>> > >>> Thanks, > >>> Chris > >>> -- > >>> Chris Suich > >>> chris.su...@netapp.com > >>> NetApp Software Engineer > >>> Data Center Platforms Cloud Solutions > >>> Citrix, Cisco & Red Hat > >>> > >>> > > > > -- *Mike Tutkowski* *Senior CloudStack Developer, SolidFire Inc.* e: mike.tutkow...@solidfire.com o: 303.746.7302 Advancing the way the world uses the cloud<http://solidfire.com/solution/overview/?video=play> *™*
