Yes and No:) Yes, as all the hypervisors(KVM/Vmware/Xenserver) still need NFS in 4.2, even S3 is used as the place to store templates. No, we make NFS is optional, if you don't want to use NFS. E.g the HyperV implementation will not depend on NFS.
In 4.3, we can start work on the hypervisor side refactor, to eliminate the dependence on NFS as much as possible, then we may can truly make the statement that, S3 will be the "secondary storage". > -----Original Message----- > From: John Burwell [mailto:jburw...@basho.com] > Sent: Wednesday, June 19, 2013 11:00 AM > To: Edison Su > Cc: dev@cloudstack.apache.org > Subject: Re: NFS Cache storage query > > Edison, > > For 4.2, are we going to state that the object store is just a backup of NFS > (i.e. > the same as 4.1)? > > Thanks, > -John > > On Jun 19, 2013, at 1:58 PM, Edison Su <edison...@citrix.com> wrote: > > > > > > >> -----Original Message----- > >> From: John Burwell [mailto:jburw...@basho.com] > >> Sent: Wednesday, June 19, 2013 10:42 AM > >> To: dev@cloudstack.apache.org > >> Cc: Edison Su > >> Subject: Re: NFS Cache storage query > >> > >> Chip, > >> > >> Your concern had not occurred to me -- making me realize that either > >> destroy or a zone attach/detach operation for the staging/temporary > >> area mechanism in 4.2. Thinking through it, there are two types of > >> operations occurring with the staging/temporary area. The first is > >> data being pulled from the object store to support some activity > >> (e.g. copying a template down to create a VM). From a data integrity > >> perspective, it is safe to kill these operations since the data has already > been persisted to the object store. > >> The second is data being pushed to the object store which are much > >> more problematic. Of particular concern would be snapshots that are > >> in the staging/temporary area, but not yet transferred to the object store. > >> > >> Edison/Min: Does the current implementation provide a destroy or > >> attach/detach behavior? If so, how are in-flight operations handled > >> to ensure there is no data loss? > > > > The current mater branch, there is no such operation for secondary storage > yet, so does the object_store branch. > > Maybe we can discuss/implement a better life cycle management of both > nfs secondary storage and staging area in collab next week. > > > >> > >> Thanks, > >> -John > >> > >> On Jun 19, 2013, at 1:26 PM, Chip Childers > >> <chip.child...@sungard.com> > >> wrote: > >> > >>> On Wed, Jun 19, 2013 at 01:23:47PM -0400, John Burwell wrote: > >>>> Chip, > >>>> > >>>> Good catch. Yes, we need definitely need a create > >>>> staging/temporary > >> area API call. However, destroy is a bit more complicated due > >> in-flight operations. Given the complexities and time pressures, I > >> recommend supporting only create in 4.2, and addressing delete in > >> 4.3. Does that make sense? > >>>> > >>> > >>> If the existence of the staging datastore blocks the deleting of a > >>> zone, or any other entity, then that doesn't work for me. > >>> > >>> I'd rather give an operator the ability to decide how to best ensure > >>> that in-flight operations are halted (i.e.: block users from the > >>> environment or something else), than not give them a way to change > >>> their configuration. > >>> > >>>> Thanks, > >>>> -John > >>>> > >>>> On Jun 19, 2013, at 1:11 PM, Chip Childers > >>>> <chip.child...@sungard.com> > >> wrote: > >>>> > >>>>> On Wed, Jun 19, 2013 at 01:07:29PM -0400, John Burwell wrote: > >>>>>> Nitin, > >>>>>> > >>>>>> If we provide any APIs for the staging/temporary area, they must > >>>>>> be > >> read-only. Allowing any external manipulation of its content could > >> cause break in-flight transfers or cause data loss. I think we > >> should consider the following APIs: > >>>>>> > >>>>>> List contents including name, reference count, and size Summary > >>>>>> statistics for a staging area including consumed/available/total > >>>>>> space and timestamp of the last garbage collection operation > >>>>>> Force garbage collection/cleanup operation > >>>>>> > >>>>>> I think we should these are new API calls specific to the > >> staging/temporary area mechanism rather than trying to overload > >> existing API calls. > >>>>>> > >>>>>> Thanks, > >>>>>> -John > >>>>> > >>>>> What about creating / destroying them? > >>>> > >>>> > >
