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From Marcus <shadow...@gmail.com>
Subject Re: Cloudstack and KVM clusters,
Date Tue, 31 Mar 2015 22:12:48 GMT
Don't forget SharedMountPoint. This (in theory, haven't tried it
recently) allows you to use any clustered filesystem that has a
consistent mountpoint across all KVM hosts in a CS cluster, e.g. mount
an OCFS2 to /vmstore1 then register /vmstore1 as a SharedMountPoint.

The Ceph support is in the form of RBD, by the way. You could use
CephFS if you wished via SharedMountPoint.

On Tue, Mar 31, 2015 at 2:09 PM, Simon Weller <sweller@ena.com> wrote:
> The hosts need to be part of the same Cloudstack cluster, and depending on the underlying
storage technology, you may need a clustered file system as well.
>
> A Cloudstack cluster is basically a group of physical hosts.
>
> For example:
>
> You build a new Zone in Cloudstack. Under the zone you have a pod. Within the pod, you
build a new cluster (just a group of hosts). Then you assigned 4 servers (hosts) into that
cluster. You will be able to live migrate between the 4 hosts assuming the original mentioned
criteria are met.
>
> - Si
>
> ________________________________________
> From: Rafael Weingartner <rafaelweingartner@gmail.com>
> Sent: Tuesday, March 31, 2015 4:02 PM
> To: dev@cloudstack.apache.org
> Cc: users@cloudstack.apache.org
> Subject: Re: Cloudstack and KVM clusters,
>
> Thanks Simon,
>
>
> I think I got it.
>
> So, the hosts do not need to be in a cluster to perform the live migration.
>
> On Tue, Mar 31, 2015 at 5:59 PM, Simon Weller <sweller@ena.com> wrote:
>
>> Rafael,
>>
>> KVM live migration really relies on whether the underlying shared storage
>> (and file system) supports the ability to provide data consistency during a
>> migration. You never ever want a situation where 2 hosts are able  to mount
>> and write to the same volume concurrently.
>>
>> You can live migrate in KVM today using the following underlying file
>> systems/methods:
>>
>> 1. NFS
>> 2. CEPH
>> 3. Clustered Logical Volume Management (CLVM) on top of SAN exposed
>> storage via iSCSI,FC or FCOE.
>>
>> It's also possible to build your own storage driver and set a LUN to read
>> only on a particular host using your SANs API.
>>
>> Solidfire, Nexenta and Cloudbyte have also added storage drivers more
>> recently that may provide support for live migration, but as I'm not
>> personally familiar with these storage platforms, I'll leave it up to
>> others to comment if they wish.
>>
>> - Si
>>
>>
>>
>>
>>
>> ________________________________________
>> From: Rafael Weingartner <rafaelweingartner@gmail.com>
>> Sent: Tuesday, March 31, 2015 3:36 PM
>> To: users@cloudstack.apache.org; dev@cloudstack.apache.org
>> Subject: Cloudstack and KVM clusters,
>>
>> Hi folks,
>>
>> I was looking a matrix of Cloudstack compatibility matrix at
>> http://pt.slideshare.net/TimMackey/hypervisor-31754727,
>>
>> Slide 25 seemed to show that we cannot have clusters of KVM in CS? Is that
>> true? Is it possible to live migrate VMs between KVM hosts that are not
>> clustered in CS?
>>
>>
>> --
>> Rafael Weingärtner
>>
>
>
>
> --
> Rafael Weingärtner

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