Datastores across vcenters and clusters

[Juice78]

Hi,

We have an old ESXi 5.1 cluster that we are phasing out. It's storage is presented from an iSCSI SAN (lefthand).

We have new servers with ESXi 6.5 installed and they have been installed into a separate vcenter. The storage is presented out from a new Fibre channel SAN (compellent).

We are trying to figure out the best way to migrate VMs from one to the other. The current idea being floated is that we present the same iSCSI SAN volumes to the new 6.5 hosts as well. We then shut down the VMs in stages and migrate them to the new datastores running from the fibre. SAN.

My questions are:

1) Are there any issues or concerns in presenting the iSCSI SAN volumes to ESXi 5.1 and 6.5 clusters that reside in separate vcenters? 

2) Is there a smarter way to do this that we are missing?

Thanks

[rcporto]

1) Are there any issues or concerns in presenting the iSCSI SAN volumes to ESXi 5.1 and 6.5 clusters that reside in separate vcenters?

Assuming you will use that scenario just during the migration, there will be no problem. Just make sure to do not enable Storage I/O Control, since that feature is supported only when a datastore is managed by a single vCenter.

2) Is there a smarter way to do this that we are missing?

Upgrade your hosts to version 5.5 and add them to the vCenter 6.5 is another approach, but will require a lot of administrative effort... so I think your approach is a good one.