Assuming you control the environment, the migration should be possible.
First is migrating VMs to the new hosts:
- Connect the new hosts to the old datastores on the old SAN.
- Create new datastores on the new SAN, and connect the new hosts to them.
- Connect the new hosts to the current distributed switch(es), so that VMs will still have connectivity.
- Add the new hosts into the existing cluster.
- Put the old hosts into maintenance mode, in order to migrate the current VMs to the new hosts. The VMs still be running on the old SAN at this point.
Next is migrating the storage. You can do this in two different ways:
1. Add new datastores into the current storage DRS cluster and put the old ones into maintenance mode.
2. Make a new storage DRS cluster, and change the storage profiles for all the vApps/VMs to use it. This will require more work, but may be a better option.
As long as you are using the same vCenter server, same vCloud environment, and that you can connect the new hosts to the old SAN, this should be able to be done live.
Alternatively, you could connect the old hosts to the new SAN, instead of connecting the new hosts to the old SAN.
Make sure you test this with a test cluster first before migrating anything production!
