ONTAP Discussions

7-mode to cDot migration - Split 7-mode HA pair?




  No idea if this is possible or a good idea Robot tongue


Essentially I have a DR HA pair of 3240s.

- Currently running 7-mode 7.3.5 with 32bit aggregates.

- Have a brand new 4TB shelf attached which they can't recognise without DOT upgrade (!).


I can borrow a loaner filer/controller from netapp and swing it out/in:

    - However was wondering on feasibility of breaking HA pair, configuring one controller in cDOT, bringing new disk shelf online (destroying the non-existant data on it) then running them in paralell and migrating across my data (essentially host based and storagevMotion etc).

   - Once data migrated I can blow away my 32bit aggregates and add 2nd node to the cluster.




- Appreciated.




That sounds acheivable. Is it a dual chassis config?

The big chunks are documented, but you'd have to fill in some pieces.  


The Active/Active configuration guide has a section on converting an HA pair into two standalone controllers.



Once you have two standalone controllers the migration should be straightforward.  Then follow the docs on converting a single node cluster into a 2 node switchless.   Along the way you'll need all new license keys, cluster network adapters, etc.  And you'll be a panic away from an outage the entire time.


Lots of potential gotchas, so talk to support if you're seriously considering it.






Hi my friend,


This is neto from Brazil


How are you?


Technically I do not see why not.


My point is: are you going to run without HA for how long?


Ping me if you need any help.




All the best




might be feasible, technically ... but sounds complicated and definitely has lot of pitfalls, which could only be handled with lot of NetApp-experience.

regarding complicated: you probably need first to move away the data from one controller, then move it to cluster, then rebalance it once the cluster is finished, so you move your data around and around ...

regarding pitfalls: if HA is single chassis you need to manipulate chassis configuration. Also I don't think that it is even possible to set up cDOT in single node cluster mode when second controller is in the chassis.  And even if: albeit there are how-tos to get from single-node to "normal" HA pair cluster configuration, it means additional work. Same for dual-chassis HA configuration.


So why not following NetApps standard procedure: get some swing gear, build up a new cluster with the 4TB disks, move the data, destroy the existing FAS3240 config and add them to the cluster (keep in mind you need disks for root-aggrs), remove the swing gear. No pain with HA/non-HA config, no single-node/multi-node reconfiguration, less data movement.

Re-use the disks from the old 32-bit aggrs if appropriate.


Hi my friend,


This is neto from Brazil


How are you?


I agree with a gear would be more feasible. But it's possible within the right procedure to do that.


The key question is: Not technical, but from a business perspective to run without HA for some time.


I agree, if this is possible to get some NetApp gear and follow the steps, would be recommended.


Please let me know how I can help.