Yes, perhaps. I'm not sure it's specific to storage provider type though, but VMware vs Xen or KVM. There are plenty of features that aren't cross-hypervisor, so perhaps if it's a hangup then the feature can be only implemented on supported hypervisors.
On Fri, Mar 28, 2014 at 5:10 PM, Mike Tutkowski <mike.tutkow...@solidfire.com> wrote: > Let me illustrate this with an example: > > * User creates a VM whose root disk is placed on managed storage > > * Storage plug-in creates a volume on its SAN > > * VMware server resource creates a datastore based on the newly created SAN > volume (let me stress that this datastore was created by the VMware server > resource - not manually by an admin as would be the case for non-managed > storage) > > * Inside the datastore are placed the VMDK file (root disk) along with VM > config files like VMX, NVRAM, etc. > > * User detaches the root volume (the VMDK file and VM config files remain in > the datastore) > > * User attaches another root volume to the VM (the VMDK file is stored in a > datastore different from the datastore where the VM config files reside, > which is fine for now) > > * User deletes and expunges the original root disk (this leads to the > datastore the VMDK file is on being removed...as a side effect, you will > also lose your VM config files), SAN volume is deleted, CloudStack volume is > marked as deleted in the database > > > On Fri, Mar 28, 2014 at 5:05 PM, Mike Tutkowski > <mike.tutkow...@solidfire.com> wrote: >> >> So, do you guys see my concern with VMware, though? >> >> VMware is different from XenServer and KVM in that its VM config files are >> stored in the datastore along side the root volume (in CloudStack 4.3, for >> example). >> >> If you switch the VM to use a VMDK file in a different datastore, the >> config files will remain in the original datastore (unless we transfer them >> ourselves to the new datastore). >> >> If they remain in the original datastore and that disk is deleted later, >> the datastore that contains that disk will be removed (along with the VM >> config files that are new being used in conjunction with a disk in another >> datastore). >> >> >> On Fri, Mar 28, 2014 at 4:58 PM, Alena Prokharchyk >> <alena.prokharc...@citrix.com> wrote: >>> >>> >>> >>> On 3/28/14, 3:50 PM, "Marcus" <shadow...@gmail.com> wrote: >>> >>> > I see this feature as mainly just shuffling around object properties >>> >in the database. I don't expect any major issues to arise with any >>> >storage if an inactive "root" disk is marked as a "data" disk in the >>> >DB, for example. In the end, when you start a VM you're always going >>> >to have a root disk in the vm instance object, and volumes that are >>> >attached/detached are going to be passed as data disks (If I >>> >understand correctly). It doesn't really matter to the storage drivers >>> >if the volume object was previously of type root or data. >>> >>> Correct. That¹s what I reflected in the spec. But I¹m going to test it on >>> all major supported hypervisors - KVM/Xen/VmWare - anyway, just to be >>> 100% >>> sure nothing breaks. >>> >>> >>> >>> > >>> >On Fri, Mar 28, 2014 at 12:48 PM, Alena Prokharchyk >>> ><alena.prokharc...@citrix.com> wrote: >>> >> I will look into it more, Mike. vmWare indeed can be different. >>> >> >>> >> -Alena. >>> >> >>> >> From: Mike Tutkowski >>> >><mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com>> >>> >> Date: Friday, March 28, 2014 at 11:39 AM >>> >> To: Alena Prokharchyk >>> >><alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>> >>> >> Cc: "dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>" >>> >><dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>> >>> >> Subject: Re: [PROPOSAL] ROOT volume detach - feature for CS 4.5 >>> >> >>> >> VMware is also different because when you shut a VMware VM down from >>> >>CloudStack, the VM still exists in vCenter Server (whereas for >>> >> XenServer >>> >>and KVM, the VM is gone). >>> >> >>> >> Since the life of a datastore that was created for managed storage is >>> >>tied to the life of the CloudStack volume it stores, when the >>> >> CloudStack >>> >>volume is deleted, the datastore goes away, as well. >>> >> >>> >> If the datastore in question was automatically created to store a root >>> >>disk (alongside VM config files) and you switch the VM to another root >>> >>disk (which has to necessarily be in another datastore), you won't see >>> >> a >>> >>problem until the original root volume is expunged by CloudStack. At >>> >>this point, its datastore will go away along with your VM config files. >>> >> >>> >> >>> >> On Fri, Mar 28, 2014 at 12:31 PM, Mike Tutkowski >>> >><mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com>> >>> >>wrote: >>> >> Well, the reason I brought it up was mainly due to VMware. >>> >> >>> >> Let's use that as an example: >>> >> >>> >> I initiate the process of spinning up a VM based on managed storage. >>> >> A volume is dynamically created on a SAN. >>> >> VmwareStorageProcessor dynamically creates a datastore to consume the >>> >>newly created SAN volume. >>> >> All VMware VM files (ex. VMX, NVRAM) are placed in the datastore >>> >>alongside the VMDK file that represents the root volume. >>> >> >>> >> Now, let's say we want to detach this root volume and give the VM a >>> >> new >>> >>root volume. >>> >> >>> >> The new root volume will necessarily be on a different datastore than >>> >>the datastore of the previous root volume (because a datastore created >>> >>to consume managed storage will have at most one VMDK file*). >>> >> >>> >> Is it going to be a problem that the VM's files (ex. VMX, NVRAM) are >>> >> on >>> >>one datastore, but its root disk is on another? >>> >> >>> >> I don't think it's really a problem until you go to delete the >>> >> original >>> >>root volume from CloudStack. At that point, its datastore will be >>> >>removed (including, of course, your VM's VMX, NVRAM, etc. files). >>> >> >>> >> This is not really a problem on XenServer because XenServer does not >>> >>store VM config files in the SR, so I think we're OK there. >>> >> >>> >> We should also be OK for KVM. >>> >> >>> >> * Technically it can have many if those other VMDK files are delta >>> >>snapshots, but they still - together - represent a single disk. >>> >> >>> >> >>> >> On Fri, Mar 28, 2014 at 10:36 AM, Alena Prokharchyk >>> >><alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>> >>> >>wrote: >>> >> Mike, thank you for the explanation on managed storage.. As far as I >>> >>understand from your email, the main difference is instead of creating >>> >>an SR on the PS, CloudStack will recognize pre-existing volume created >>> >>outside of the CS. Am I correct? >>> >> >>> >> If so, I don't think there would be any difference. When root volume >>> >>detach happens, no storage attributes - path, clusterId - are being >>> >>changed. And we would apply the same set of checks to the root volume >>> >>attach, as for a dataDisk attach. >>> >> >>> >> -Alena. >>> >> >>> >> From: Mike Tutkowski >>> >><mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com>> >>> >> Date: Thursday, March 27, 2014 at 9:40 PM >>> >> To: Alena Prokharchyk >>> >><alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>> >>> >> Cc: "dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>" >>> >><dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>> >>> >> Subject: Re: [PROPOSAL] ROOT volume detach - feature for CS 4.5 >>> >> >>> >> Hi Alena, >>> >> >>> >> I was wondering if you've taken "managed" storage into consideration >>> >>for this? >>> >> >>> >> If you're unfamiliar with it, managed storage is named as such because >>> >>CloudStack manages it on behalf of the admin (ex. dynamically creating >>> >>SRs as needed). >>> >> >>> >> For example, when I add primary storage to CloudStack that is based on >>> >>the SolidFire SAN, I use the SolidFire plug-in, which is an example of >>> >>managed storage. >>> >> >>> >> In this case, the primary storage represents a SAN as opposed to a >>> >>preallocated volume. >>> >> >>> >> When the time comes to, say, attach a data disk to a VM for the first >>> >>time, the SolidFire plug-in goes off to its SAN and dynamically creates >>> >>a new volume on it (with the appropriate size and IOPS requirements). >>> >> >>> >> CloudStack has logic that recognizes managed storage. >>> >> >>> >> For example, for XenServer, its logic has been augmented to >>> >>automatically create an SR based on the iSCSI target that was created >>> >> on >>> >>the SAN and to create a VDI within it that is attached to the VM in >>> >>question. >>> >> >>> >> The big takeaway is that each CloudStack volume here will be >>> >> associated >>> >>with a unique volume on a SAN and consumed as an SR (XenServer) or >>> >>datastore (ESX) (KVM handles this differently). In this situation, >>> >> there >>> >>is a 1:1 mapping between a SAN volume and an SR. No other VDIs are >>> >>stored on the SR except for the one representing this one CloudStack >>> >>volume. >>> >> >>> >> That being the case, I was wondering what you thought of this with >>> >>regards to your root-volume-detach feature? >>> >> >>> >> If we don't want to look into this for 4.5, it might be best to simply >>> >>fail to detach a root volume from a VM if the volume is based on >>> >> managed >>> >>storage or to fail to attach a bootable volume to a VM if it is based >>> >> on >>> >>managed storage. >>> >> >>> >> Talk to you later, >>> >> Mike >>> >> >>> >> >>> >> On Tue, Mar 25, 2014 at 1:24 PM, Alena Prokharchyk >>> >><alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>> >>> >>wrote: >>> >> Mike, >>> >> >>> >> Volume has a template_id referencing vm_template table. Vm_template >>> >> has >>> >> bootable flag, so we will derive information from there. >>> >> And sure, this information will not change if the root disk is >>> >> detached. >>> >> >>> >> On 3/25/14, 12:18 PM, "Mike Tutkowski" >>> >><mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com>> >>> >> wrote: >>> >> >>> >>>Hi Alena, >>> >>> >>> >>>I was wondering how we plan to keep track of the new "bootable" >>> >>>property? >>> >>>When we create a VM, would we just mark its root disk as bootable and >>> >>>then >>> >>>that property becomes immutable (for the upgrade case, all root disks >>> >>>would >>> >>>be marked as bootable)? >>> >>> >>> >>>I'm thinking we'd want to keep track of bootable disks even when there >>> >>>are >>> >>>detached and turned into data disks. Is that what you had in mind? >>> >>> >>> >>>Thanks! >>> >>>Mike >>> >>> >>> >>> >>> >>>On Tue, Mar 25, 2014 at 12:20 PM, Alena Prokharchyk < >>> >>>alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>> >>> >>>wrote: >>> >>> >>> >>>> Here is the link to the corresponding FS (placed in "4.5 Design >>> >>>>documents" >>> >>>> section) >>> >>>> >>> >>>> >>> >>> >>>> >>>>https://cwiki.apache.org/confluence/display/CLOUDSTACK/ROOT+volume+deta >>> >>>>ch >>> >>>> >>> >>>> -Alena. >>> >>>> >>> >>>> From: Alena Prokharchyk >>> >>> >>>> >>>><alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com><mail >>> >>>>to: >>> >>>> alena.prokharc...@citrix.com<mailto:alena.prokharc...@citrix.com>>> >>> >>>> Date: Monday, March 24, 2014 at 11:37 AM >>> >>>> To: >>> >>> >>>> >>>>"dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org><mailto:dev >>> >>>>@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>>" < >>> >>>> >>> >>> >>>> >>>>dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org><mailto:dev@ >>> >>>>cloudstack.apache.org<mailto:dev@cloudstack.apache.org>>> >>> >>>> Subject: [PROPOSAL] ROOT volume detach - feature for CS 4.5 >>> >>>> >>> >>>> I would like to propose a new feature for CS 4.5 - "ROOT volume >>> >>>>detach" >>> >>>>- >>> >>>> that enables support for following use cases: >>> >>>> >>> >>>> 1) Replace current ROOT volume with the new one for existing vm. >>> >>>> 2) Case when ROOT volume of vm1 gets corrupted, and you want to >>> >>>> attach >>> >>>>it >>> >>>> to vm2 to run the recovery utils on it. With current CS >>> >>>> implemntation, >>> >>>>you >>> >>>> have to perform several steps - create snapshot of vm1's volume, >>> >>>>create >>> >>>> volume from snapshot, attach volume to the vm2. New implementation >>> >>>>will >>> >>>> merge it all to one step. >>> >>>> >>> >>>> >>> >>>> With the planned implementation, once the ROOT volume is detached, >>> >>>> it >>> >>>>can >>> >>>> be attached to any existing vm (with respect to >>> >>>> Admin/Domain/Physical >>> >>>> resources limitations), either as a DataDisk or a Root disk. >>> >>>> >>> >>>> Amazon EC2 already has this functionality in place, so I think CS >>> >>>>would >>> >>>> only benefit from having it. Storage experts (Edison, others) please >>> >>>>raise >>> >>>> your concerns if you have any, or if you see any potential problems >>> >>>>with >>> >>>> the planned implementation. And if anyone can think of other use >>> >>>> cases >>> >>>>this >>> >>>> feature can possible solve, I would appreciate this input as well. >>> >>>> >>> >>>> >>> >>>> Feature limitations: >>> >>>> >>> >>>> * ROOT volume can be detached only when vm is in Stopped state >>> >>>> * CS will fail to start the vm not having a ROOT volume >>> >>>> >>> >>>> I will send out the link to the FS once I start getting feedback on >>> >>>>the >>> >>>> proposal. >>> >>>> >>> >>>> -Alena. >>> >>>> >>> >>> >>> >>> >>> >>> >>> >>>-- >>> >>>*Mike Tutkowski* >>> >>>*Senior CloudStack Developer, SolidFire Inc.* >>> >>>e: mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com> >>> >>>o: 303.746.7302<tel:303.746.7302> >>> >>>Advancing the way the world uses the >>> >>>cloud<http://solidfire.com/solution/overview/?video=play> >>> >>>*(tm)* >>> >> >>> >> >>> >> >>> >> >>> >> -- >>> >> Mike Tutkowski >>> >> Senior CloudStack Developer, SolidFire Inc. >>> >> e: mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com> >>> >> o: 303.746.7302<tel:303.746.7302> >>> >> Advancing the way the world uses the >>> >>cloud<http://solidfire.com/solution/overview/?video=play>(tm) >>> >> >>> >> >>> >> >>> >> -- >>> >> Mike Tutkowski >>> >> Senior CloudStack Developer, SolidFire Inc. >>> >> e: mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com> >>> >> o: 303.746.7302<tel:303.746.7302> >>> >> Advancing the way the world uses the >>> >>cloud<http://solidfire.com/solution/overview/?video=play>(tm) >>> >> >>> >> >>> >> >>> >> -- >>> >> Mike Tutkowski >>> >> Senior CloudStack Developer, SolidFire Inc. >>> >> e: mike.tutkow...@solidfire.com<mailto:mike.tutkow...@solidfire.com> >>> >> o: 303.746.7302 >>> >> Advancing the way the world uses the >>> >>cloud<http://solidfire.com/solution/overview/?video=play>(tm) >>> >> >> >> >> -- >> Mike Tutkowski >> Senior CloudStack Developer, SolidFire Inc. >> e: mike.tutkow...@solidfire.com >> o: 303.746.7302 >> Advancing the way the world uses the cloud(tm) > > > > > -- > Mike Tutkowski > Senior CloudStack Developer, SolidFire Inc. > e: mike.tutkow...@solidfire.com > o: 303.746.7302 > Advancing the way the world uses the cloud(tm)
