I have a FAS220 with an external SAS shelf with 24 disks DS2246, this is a single controller, we need to add it and rebuilt the root aggr to have 2 root aggr.
Something that we're thinking is performing option 4 on the boot menu, however, the SAS shelf won't be clean we will be taking out the shelf, then after we finished with the clean process we pretend to put it back again the existing shelf to the new HA and hopefully, everything will be working as expected.
The platform is FAS2220, and what I trying to do is add a second controller, but all the data will be move to the SAS shelf then we're going to destroy root aggr, basically option 4, then with the internal chassis recreate 2 root aggr with 2 root volumes in order to have an HA.
We can add it right now because we don't have enough disk available to create an aggr, we want to separate half of them to a controller and the other half to the other controller, then when everything cabled working as expected we pretend to add the external shelf [that shelf is not clean it has all data], plugin and hopefully, NetApp recognizes and continue sharing the data in it.
My concern is this procedure is valid and I want to verify if the sysid that the external disks have will the same one and won't be any issue or misunderstanding between Netapp controllers and the external shelf.
The disconnected AGGR should be able to get recognized again when connected. In 7-Mode the metadata only exists on the disks themselves and not on the root/boot partitions.
The only concern I will have is about licensing. Do you have 8.2+ and HA licence for both controllers? ONTAP 8.2 licence only work for the controller s/n it has been issued to, and only with licences specifically generated for ONTAP 8.2+.
If these systems been sold with earlier version, and you don't have the 28 chars long licence keys for both controllers - DO NOT PROCEED with the option 4 plan.