Metrocluster expansion 1 node + 1 Node (each site) and Upgrade to 9.0


I'm posting that message hoping that maybe someone was going through similar upgrade and can share his experiences.
I do not have any specific issues so far, i'm rather brainstorming and going through risk assesment.

Current architecture:

There are only 2 controllers FAS8040 CDOT 8.3.2RC2 connected via Metrocluster.
It’s not the typical HA pair of controllers in each site. It’s just one controller per site now. Production in Site 1 and DR in Site 2.
2 ATTO FibreBridge 6500 in each site and 2 Brocade switches 6505 for connectivity.
Only NFS and CIFS is used to provision storage to clients, with sync-source -> sync-destination relationship between sites.
FC is used only for backend metrocluster connectivity cisco mds 9506 between sites.

Task to do:
Add another controller in each site to create HA pair in each site.
Double number of disks adding another stack and another pair of ATTO FibreBridge 6500.

8 h maintanance window
New nodes will be on 9.0P2 Netapp or 9.1, which means that current nodes 8.3.2RC2 will require upgrade during the expansion.


im adding to the checklist basic tasks to be assesed whatever comes to my mind, please let me know if you have any thoughts what other risks schould be taken into account, etc

Check the impact of the upgrade to version 9 of CDOT on the following:
1. Assess if any impact on the connected CIFS client sessions
2. Assess if any impact on the connected NFS sessions
3. Assess if any impact on Qtrees and Quotas
4. Assess if any impact of Active Directory version supported by CDOT 9.0P2 and if we are currently on supported version of AD considering upgrade to CDOT 9.0P2
5. Assess if any impact on our Snapvault backups
6. Assess if any impact on the existing snapshots.
7. Assess if any impact on existing Unified Monitoring servers (Unified Manager/Performance Manager)

1. check that all network connectivity for the new NetApp controller are live