Vmotion between 3 hosts

[sAvak]

Hi,

I'm newbie in VMware and my manager asked me for this little project. I'm wondering what is the best way to accomplish that.

My environment consists 2 Hosts 6.0 that are connected with iSCSI to Dell EMC NAS storage.  I'm able to vmotion the VMs between the 2 hosts.

My Third host is 6.7 and iSCSI to Pure NAS storage. If it's not clear, the applications on this host is on a different Datastore from the other two hosts.

The goal is to be able to vmotion the VMs between the 3 hosts as well as creating HA.

Thank you,

Omri

[a_p_]

Welcome to the Community,

it's basically possible to migrate VM's without shared storage, but this involves copying the full virtual disk, etc., which requires quite some time.

To use vMotion, and HA in the usual way, all of your hosts need access to the same datastore(s).

André

[HassanAlKak88]

Hello,

VMware VMotion and Storage VMotion are products that allow the live migration of virtual machines among various physical servers, while the VMs are running, with no downtime, no interruption in service, and total transaction integrity.

For vMotion = live migration, a shared storage is required to move VMs between hosts. So for your case, the Datastore which hosts the application VM must be mounted on the three hosts to be able to move it.

For svmotion (Storage vmotion), your existing configuration you can migrate the application's VM from third host to the other but selecting both compute and storage.

[sAvak]

Thanks for the quick Replies. Stil have couple of questions.

Do I need to upgrade my first two hosts to 6.7 to match the third host?

Does it mater the hosts hardware and CPUs are different from one another.

If I understand you correctly, to make it work,  I need to move the VMs from EMC storage datastore to Pure storage storage.

Omri

[NathanosBlightc]

Do I need to upgrade my first two hosts to 6.7 to match the third host?

No, ESXi hosts do not need to be at the same version for functionality be OK. All Clustering features like HA and DRS will work without any problem. But DO NOT upgrade VM hardware compatibility version to higher version when they will migrate to host ver6.7, because if you want to migrate them back to older ESXi you cannot start them.

Does it mater the hosts hardware and CPUs are different from one another.

Live Migration are highly dependent on EVC feature and EVC is also related just to the CPU generation of your Hosts. If your hosts have different CPU platform you need to check them for EVC Compatible mode (for example Haswell, Westmere, Sandy Bridge and so on)

If I understand you correctly, to make it work,  I need to move the VMs from EMC storage datastore to Pure storage storage.

If it's only shared storage between three ESXi hosts and you want to use it as your shared storage on your cluster to HA and DRS work correctly, Yes you need to migrate them from EMC to Pure storage

[sAvak]

Thanks. Is there a way to connect between EMC datasore and Pure datastore so the 3 hosts sees it as one share datastore.

I have limited space in PURE, so I wont able to move all EMC VMs Datastore to PURE Datastore.

Thanks again,

Omri

[daphnissov]

Is there a way to connect between EMC datasore and Pure datastore so the 3 hosts sees it as one share datastore.

No, this isn't possible.

If you want the ability to vMotion a VM among this three hosts without changing the storage location, both kinds of hosts will need to mount datastores from the EMC and Pure storage.

[sAvak]

Thanks for the guide. I'll check it later.

But your last comment confused me. If I understood correctly, to be able to use vmotion and HA , all 3 ESXI hosts should be mounted to the same storage and to one shared datasore.  If I have 2 separate datasores on 2 different storage, as I have right now, Can I still use vmotion and HA, or I need to merge EMC datastre to PURE datastore.

Thanks,

Omri

[daphnissov · Accepted solution]

No, that isn't what I said. You have two separate physical arrays: One from EMC and one from Pure. You have hosts (let's call them A and B) mounting EMC storage. You have a third host (let's call this one C) mounting Pure storage. You have a VM that resides on the EMC storage currently running on host A. You want to vMotion that VM to host C. In order to do this, host C must also be mounting the EMC storage. Vice versa for VMs stored on Pure that you want to migrate to host A or B. This will result in two different datastores (one EMC and one Pure) that are mounted to ​all three hosts​.

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