upgrade ONTAP

[mulbzh]

hello and sorry for my english,

I always do updates on my Netapp equipment. I now in version 9.15.1P17 on all clusters !

I'd like now to upgrade to new version. I have:
AFF-C250
FAS2720
FAS2820

Witch version i have to choose for upgrade ? 9.16, 9.17 or 9.18 ?
i'd like same version on all clusters, easier...

Can i have troubles when upgrade ?

i use CIFS share, ISCSI volumes and NFS volumes for Vmware, Consistency group with mediator (business continuity), snapmirror, antiransomware

thanks a lot

[elementx]

There are almost always known (and unknown) issues, but those are indicated in release notes and other documents.

There are different ways to upgrade - e.g. incrementally or directly

https://docs.netapp.com/us-en/ontap/upgrade/concept_upgrade_paths.html#types-of-upgrade-paths

For your version direct to latest is possible:

https://docs.netapp.com/us-en/ontap/upgrade/concept_upgrade_paths.html#from-ontap-9-8-and-later

You can review release notes and the IMT (for any issues or notes) to see which one you prefer.