Yeah, that's why I started the conversation saying we might just want to prohibit this operation for managed storage in 4.5 until we can think it through and make it work for all supported hypervisors. :)
As I say, I think it will be fine for XenServer and KVM as they do not store VM config files the way VMware does. On Fri, Mar 28, 2014 at 5:15 PM, Marcus <shadow...@gmail.com> wrote: > 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) > -- *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> *(tm)*
