I need some extra eyes to look at a migration process we are thinking of undertaking. Here's the situation:
Old Environment:
5 ESX hosts running 5.1 connected to vCenter 5.1
~170 VMs running
EqualLogic SAN
One host connected to new Compellent storage array
Gigabit network
New Environment:
2 ESX hosts running 5.5 connected to vCenter 5.5 (new instance)
Compellent SAN
10 Gigabit network
We want to move the VMs from the old environment to the new without taking a restart of the VMs if possible. The process proposed by our implementation partner is to:
1. vMotion the VMs on the old host which is connected to Compellent
2. Storage vMotion to the Compellent disk
3. Power the VMs down
4. Remove the VMs from inventory on the old vCenter
5. Add the VMs to inventory on the new vCenter
6. Power the VMs on using one of the two new hosts
We were brainstorming today (dangerous!) and wondered about this process:
1. vMotion the VMs to an old host with Compellent connectivity
2. Add the old host to the new vCenter (causing it to disconnect from the old vCenter)
3. vMotion the VMs from the old host to one of the new hosts from within the new vCenter
This seems to be a no down time approach. Since the servers will all be running on the host while the host moves between vCenters, the only real exposure I'm seeing is during the time between vCenters, there is no other host to pick up the VMs if something failed. The servers are all Intel processors and of a similar age so I don't think EVC will be an issue. We can then restart as we see fit to upgrade VMware Tools and Virtual Hardware. Can someone help poke holes in this or tell me we're on the right path?
Yes, absolutely you can do these operations without any outage.
If you are doing this by using UI (VI client or Web client)
1. First vMotion all the VMs from other 4 old host to a old host where compellent storage array access available.
-Make sure old host with compellent access has enough CPU/Memory so that all ON VMs can be placed.
- Also make sure all old host have shared storage array except compellent (that is available on one old host), I think it is there already.
2. Now storage vMotion all the VMs to old host compeleent storage array.
-This can be done using script or manually
3. Remove old host (with compellent ) from older vCenter server.
4. Create one cluster on new 5.5 vCenter and add all host (1 old + 2 new ) to cluster.
5. Enable DRS in fully automated mode with aggressive threshold. and make sure vMotion network is configured properly.
6. Put old host into maintenance mode. DRS will automatically vacate the old host and balance the load on other new hosts as well.
7. Wait for all the vMotion operation to complete, old host wud be now in Maintenace mode.
8. Remove old host from cluster and exit from MM and remove from new vCenter.
Note:
-You can configure VMware HA/FT on the cluster to avoid any possible failure (Make sure you satisfy HA/FT requirement)
-If possible explore XVMotion, which helps to relocate VM even there is no shared datastore.
-If you want to use script to do vMotion/SVMOtion, get back to me.
-Let me know if you have any doubt
Plz award points if this is useful.
Hi,
if your CPUs on the old and new servers are vMotion compatible, you can indeed achieve the migration without any downtime with the way you described.
1. Storage vMotion the VMs to the compellent
2. vMotion the VMs to the old host with compellent access
3. remove host from old vCenter
4. add host to new vCenter
5. vMotion VMs to the new hosts.
I guess you have to repeat this steps a few times, as your one host can't take all 170 VMs at once and probably shouldn't with a gigabit connection to the compellent ![]()
Regards
Tim
Yes, absolutely you can do these operations without any outage.
If you are doing this by using UI (VI client or Web client)
1. First vMotion all the VMs from other 4 old host to a old host where compellent storage array access available.
-Make sure old host with compellent access has enough CPU/Memory so that all ON VMs can be placed.
- Also make sure all old host have shared storage array except compellent (that is available on one old host), I think it is there already.
2. Now storage vMotion all the VMs to old host compeleent storage array.
-This can be done using script or manually
3. Remove old host (with compellent ) from older vCenter server.
4. Create one cluster on new 5.5 vCenter and add all host (1 old + 2 new ) to cluster.
5. Enable DRS in fully automated mode with aggressive threshold. and make sure vMotion network is configured properly.
6. Put old host into maintenance mode. DRS will automatically vacate the old host and balance the load on other new hosts as well.
7. Wait for all the vMotion operation to complete, old host wud be now in Maintenace mode.
8. Remove old host from cluster and exit from MM and remove from new vCenter.
Note:
-You can configure VMware HA/FT on the cluster to avoid any possible failure (Make sure you satisfy HA/FT requirement)
-If possible explore XVMotion, which helps to relocate VM even there is no shared datastore.
-If you want to use script to do vMotion/SVMOtion, get back to me.
-Let me know if you have any doubt
Plz award points if this is useful.
