Trying to understand the mixed storage configuration options.
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available. I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems). When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time. Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design? Any assistance/guidance is greatly appreciated.
On Thu, May 12, 2016 at 4:50 AM, Jason Ziemba <jason@ziemba.net> wrote:
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available.
I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems).
When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time.
Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design?
Any assistance/guidance is greatly appreciated.
_______________________________________________
Already asked about one month ago. See thread here: http://lists.ovirt.org/pipermail/users/2016-April/038911.html The last comment by Neil was to provide reasons for this need, as probably it is not on the roadmap. But 4.0 version is only at alpha stage so we can influence it, if we push. Actually already in 2013 it was asked and Itamar at that time wrote that the team was working on eliminating this limit.. don't know what exactly was the design limitation from a technical point of view. See thread with question from (another one... ;-) Jason here: http://lists.ovirt.org/pipermail/users/2013-July/015400.html and Itamar final comment here: http://lists.ovirt.org/pipermail/users/2013-July/015413.html I'm favorable to have the chance to configure inter-mixed storage, local and not, especially for testing purposes, but not only, where you have plenty of storage you cannot dedicate to oVirt VMs now. The workaround is to have it seen as NFS storage, but it makes sense only for one-host configuration in my opinion, and it overloads network when it is not necessary. Can we vote for it? Do we need to open an RFE? BTW: I think insipration should also come form what the leaders are doing (in the positive sense) and in what's new for vSphere 6 here: https://www.vmware.com/files/pdf/vsphere/VMW-WP-vSPHR-Whats-New-6-0-PLTFRM.p... you find explicitly inside the "VMware vSphere Fault Tolerance Enhancements", so in a critical infrastructure point: " There have also been enhancements in how vSphere FT handles storage. It now creates a complete copy of the entire virtual machine, resulting in total protection for virtual machine storage in addition to compute and memory. It also increases the options for storage by enabling the files of the primary and secondary virtual machines to be stored on shared as well as local storage. This results in increased protection, reduced risk, and improved flexibility " food to the discussion ;-) Gianluca
On Thu, May 12, 2016 at 10:50 AM, Gianluca Cecchi <gianluca.cecchi@gmail.com> wrote:
On Thu, May 12, 2016 at 4:50 AM, Jason Ziemba <jason@ziemba.net> wrote:
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available.
I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems).
When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time.
Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design?
Any assistance/guidance is greatly appreciated.
_______________________________________________
Already asked about one month ago. See thread here: http://lists.ovirt.org/pipermail/users/2016-April/038911.html
The last comment by Neil was to provide reasons for this need, as probably it is not on the roadmap. But 4.0 version is only at alpha stage so we can influence it, if we push.
No chance for 4.0. It is unlikely that we will work on it before removing the spm and the master domain. Without spm and master domain, this change should be easier.
Actually already in 2013 it was asked and Itamar at that time wrote that the team was working on eliminating this limit.. don't know what exactly was the design limitation from a technical point of view. See thread with question from (another one... ;-) Jason here: http://lists.ovirt.org/pipermail/users/2013-July/015400.html
and Itamar final comment here: http://lists.ovirt.org/pipermail/users/2013-July/015413.html
Having access to all storage domains from all hosts in a dc is the basic design assumption. Having some domains which are accessible only from some hosts is a major change.
I'm favorable to have the chance to configure inter-mixed storage, local and not, especially for testing purposes, but not only, where you have plenty of storage you cannot dedicate to oVirt VMs now. The workaround is to have it seen as NFS storage, but it makes sense only for one-host configuration in my opinion, and it overloads network when it is not necessary.
Can we vote for it? Do we need to open an RFE?
I think we have one, and you can vote on the bug (I don't have the bug number).
BTW: I think insipration should also come form what the leaders are doing (in the positive sense) and in what's new for vSphere 6 here: https://www.vmware.com/files/pdf/vsphere/VMW-WP-vSPHR-Whats-New-6-0-PLTFRM.p...
you find explicitly inside the "VMware vSphere Fault Tolerance Enhancements", so in a critical infrastructure point:
" There have also been enhancements in how vSphere FT handles storage. It now creates a complete copy of the entire virtual machine, resulting in total protection for virtual machine storage in addition to compute and memory. It also increases the options for storage by enabling the files of the primary and secondary virtual machines to be stored on shared as well as local storage. This results in increased protection, reduced risk, and improved flexibility
Can you explain what they are doing and how it can benefit ovirt? Nir
On Thu, May 12, 2016 at 5:50 AM, Jason Ziemba <jason@ziemba.net> wrote:
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available.
I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems).
When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time.
Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design?
This is not available by design. Can you explain the use case, why do you need to use local storage as your primary data storage? How are you going to migrate your vms if the primary storage is local? How are you going to start the vms on another host after host failures, if the vm storage is on the failed host, and the last state of that disk is not available or even lost? Nir
Nir, Basically, almost any server has a local storage. It could be a reliable, RAID enabled storage. It would be great to allow to use it simultaneously with shared storages. Other virtualizations like vmware/hyperv support local and shared storages simultaneously. If your VM is on local storage, it's tied to a host. Just like when VM has attached local device(s). VM migration moves disks between hosts as well. An obvious solution is to export local storages via NFS to make it shared. This would allow to drop «local storage datacenters» as a class. TODO list would be the following: 1. VDSM: add creating NFS exports 2. Engine: creating NFS exports before local storage activation, and updating NFS exports after adding/removing hosts 3. Engine: add moving disks between storages during (just before, just after) VM migration. 4. Engine: add constraints to avoid dangerous situations - disallow changing VM startup host, disallow moving disks to another local storage without VM migration, etc. On 13/05/16 14:04, "users-bounces@ovirt.org on behalf of Nir Soffer" <users-bounces@ovirt.org on behalf of nsoffer@redhat.com> wrote:
On Thu, May 12, 2016 at 5:50 AM, Jason Ziemba <jason@ziemba.net> wrote:
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available.
I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems).
When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time.
Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design?
This is not available by design.
Can you explain the use case, why do you need to use local storage as your primary data storage?
How are you going to migrate your vms if the primary storage is local?
How are you going to start the vms on another host after host failures, if the vm storage is on the failed host, and the last state of that disk is not available or even lost?
Nir _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Nir, The use cases of my current configuration is a mix of duplicated data clusters (Percona/Consul/CouchBase) and ephemeral systems (web servers) that work perfectly when 'locked' to a local host These are built in such a way that losing a physical host reduces redundancy but isn't outwardly service degrading. The other side is the duplicated databases (namely Percona) that would induce a fairly high level of NAS bandwidth that is avoided when they leverage the local storage on their host system. The goal would be to have the ability to house the highly redundant and/or ephemeral systems to be housed on the hosts local storage, whereas guests that need HA or one-offs would be housed using the NAS allowing seamless HA or online migration. On Fri, May 13, 2016 at 7:04 AM, Nir Soffer <nsoffer@redhat.com> wrote:
On Thu, May 12, 2016 at 5:50 AM, Jason Ziemba <jason@ziemba.net> wrote:
I'm fairly new to oVirt (coming from ProxMox) and trying to wrap my head around the mixed (local/NAS) data domain options that are available.
I'm trying to configure a set of systems to have local storage, as their primary data storage domain, though also want to have the ability to have a NAS based data domain for guests that are 'mobile' between hosts. Currently I'm able to do one or the other, but not both (so it seems).
When I put all of the systems in to a single cluster (or single data-center) I'm able to have the shared data domain, though have only found the ability to configure one system for local storage (not all of them). When I split them out in to separate data centers, they all have their local data domain working, but only a single dc is able to access the shared data domain at a time.
Am I missing something along the way (probably fairly obvious) that does exactly what I'm outlining, or is this functionality not available by design?
This is not available by design.
Can you explain the use case, why do you need to use local storage as your primary data storage?
How are you going to migrate your vms if the primary storage is local?
How are you going to start the vms on another host after host failures, if the vm storage is on the failed host, and the last state of that disk is not available or even lost?
Nir
participants (4)
-
Gianluca Cecchi -
Jason Ziemba -
Nir Soffer -
Pavel Gashev