Hi Alex, Please see inline.
Regards, Devdeep > -----Original Message----- > From: Alex Huang [mailto:alex.hu...@citrix.com] > Sent: Wednesday, January 16, 2013 5:47 AM > To: cloudstack-dev@incubator.apache.org > Subject: RE: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > Devdeep, > > I read the FS and have the following questions. > > - My understanding is that XenServer implements XenMotion by using > snapshots and that CloudStack's snapshots can interfere with this process. > This understanding might be old. Can you confirm that this is not the case? > If > it is the case, how do you plan on dealing with that? [Devdeep] I tried storage xenmotion on a vm whose root disk had a snapshot taken. Storage xenmotion worked, but the reference to the snapshot on the volume wasn't preserved after the operation. I need to a look more into how this will affect the snapshot functionality of cloudstack. > - I like to see exactly the API flow someone should execute this with. I had > one question that remains unanswered which is are we planning to retrieve a > list of available hosts and storage pools to migrate to. From the listHosts > API > that seems to be the case but what if it is only storage pool migration? [Devdeep] My thinking was to just update the lisHosts api to also give a list of hosts to which a vm can be migrated. If it is only storage pool migration than the admin has to specify the storage pool id in migrateVirtualMachine call and the virtual disks of the vm will be live migrated using xenmotion. Should we also provide an api for listing storage pools available for storage motion? Now that I think again about it, it does make more sense. > - Are we planning to add APIs to storagepool allocator to make the selection > of storage pool portion work? Is the current API enough? I see a flow for > the > actual migration but I don't see a flow for selecting what to migrate to. [Devdeep] I'll update the FS to include information on how selection for a storage pool is made. > - Currently preparation on the destination host to migrate is done by > management server, in the flow in the FS, it is now being done by the source > agent. What's the pros/cons of this change? I see that as an open issue on > your spec and I think if we can keep the hosts from establishing contact with > each other it will be best. [Devdeep] The current preparation (PrepareForMigrationCommand) is also applicable for storage xenmotion. TFor storage xenmotion there are a set of three apis that need to be called; migrateReceive (on dest), assertForMigrate (on src) and migrateSend (on src). The information returned by migrateReceive needs to be passed as a parameter in migrateSend. Additionally, the session created for migrateReceive should remain valid till the time storage migration completes. Is there a way to ensure this? If so, we can avoid hosts from establishing contact with each other. > - I like to see the full API speced out. [Devdeep] I'll update the FS with more details. > > I also like to see Hari's question answered. Can we provide this with VmWare > as well? [Devdeep] Sateesh was going to look at Storage vMotion for VmWare. I'll ask him to update on it. > > --Alex > > > -----Original Message----- > > From: Devdeep Singh [mailto:devdeep.si...@citrix.com] > > Sent: Tuesday, January 08, 2013 1:58 AM > > To: cloudstack-dev@incubator.apache.org > > Subject: RE: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > > > Hi Swamy, > > > > In the following scenario when a VM has disks in different > > repositories, all the virtual disks of the VM will be moved to the same > destination repository. > > Moving individual disks of the VM to different repositories can be > > done, but it'll involve taking inputs from the user as to which disk > > should be moved to which repository. What do you think, should this option > be also provided? > > > > Regards, > > Devdeep > > > > > -----Original Message----- > > > From: Venkata SwamyBabu Budumuru > > > [mailto:venkataswamybabu.budum...@citrix.com] > > > Sent: Thursday, December 27, 2012 5:42 PM > > > To: cloudstack-dev@incubator.apache.org > > > Subject: RE: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > > > > > Hi Devdeep, > > > > > > Does this also cover the following use case ? > > > > > > VM1 => ROOT (Storage Repository 1) > > > => DATA-1 (Storage Repository 2) > > > > > > Can I migrate DATA-1 vdi alone to a different repository? Or Is this > > > feature allowing the whole VM (including ROOT and DATA-1) to same > > > destination repository? > > > > > > Thanks, > > > SWAMY > > > -----Original Message----- > > > From: Hari Kannan [mailto:hari.kan...@citrix.com] > > > Sent: Thursday, December 27, 2012 2:18 AM > > > To: cloudstack-dev@incubator.apache.org > > > Subject: RE: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > > > > > Hi Devdeep, > > > > > > Should this discussion be expanded to cover VMware storage migration > > > or > > a > > > different discussion - I wish to see how we can add vSphere as a > > > supported platform for this feature.. > > > > > > Hari > > > > > > -----Original Message----- > > > From: Devdeep Singh [mailto:devdeep.si...@citrix.com] > > > Sent: Wednesday, December 26, 2012 4:44 AM > > > To: cloudstack-dev@incubator.apache.org > > > Subject: RE: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > > > > > I have created an initial draft of the FS here > > > > > https://cwiki.apache.org/confluence/display/CLOUDSTACK/Enabling+Storag > > e+ > > > XenMotion+for+XenServer. I'll keep updating it based on discussion > > > XenMotion+for+and > > > comments. > > > > > > Regards, > > > Devdeep > > > > > > > -----Original Message----- > > > > From: Devdeep Singh [mailto:devdeep.si...@citrix.com] > > > > Sent: Tuesday, December 18, 2012 2:10 PM > > > > To: cloudstack-dev@incubator.apache.org > > > > Subject: [DISCUSS] Enabling storage xenmotion on xenserver 6.1 > > > > > > > > Hi, > > > > > > > > XenServer introduced support for Storage XenMotion in the latest > > > > version (6.1). Storage XenMotion allows VMs to be moved from one > > > > host to another, where the VMs are not located on storage shared > > > > between the two hosts. It provides the option to live migrate a > > > > VM's disks along with the VM itself. It is now possible to migrate > > > > a VM from one resource pool to another, or to migrate a VM whose > > > > disks are on local storage, or even to migrate a VM's disks from > > > > one storage repository to another, all while the VM is running. > > > > More information on Storage > > > XenMotion can be found at [1]. > > > > > > > > I have filed a jira request [2] to track this feature. I plan to > > > > extend the migrate vm cloudstack api call to allow migration of > > > > instances across clusters. Do let me know your comments. > > > > > > > > [1] http://blogs.citrix.com/2012/08/24/storage_xenmotion/ > > > > [2] https://issues.apache.org/jira/browse/CLOUDSTACK-659 > > > > > > > > Regards, > > > > Devdeep
