Configuring a system with a 64-bit root aggregate in 8.0 is not recommended by NetApp
Why is this the case? Is there a technical and/or support reason?
Tirtha: As far as I know, the feature of 64-bit aggregate mainly aimed to allow users to create aggregates of size more than 16 TB and this feature has been introduced in 8.0. Ontap 8.0 though allows 64-bit and 32-bit aggregate to reside and function side-by-side, it comes with some restrictions. But sorry to say that the deep dive over 32-bit default and restriction of root volumes to 32-bit, would be possible if u refer to the technical support documents of Ontap 8.0 available in NOW or you can contact NGS.
However as an additional piece of information, autoroot is allowed in 64-bit aggregate to bring up the system quickly when the existing root can't be brought up online. After the system is brought up, it is recommended that root volume should be switched to a 32-bit volume as soon as possible.
Will autoroot be created in a 32bit aggregate if one is present?
Tirtha: Yes. AutoRoot Feature is mainly a recovery feature. In case due to some corruption or other inevitable reasons, you can recreate root volume by AUTOROOT feature. So anytime you can set up a 32-bit aggregate as root aggr and if that doe not contain a volume marked as root, Autoroot feature will create one as default.
Also, why is the 32bit aggregate a default, if the 64bit is the recommended aggregate type for 8.0 and above..?
I already answered this question of yours.
Post if you have any other doubt, if not me, others will pitch in and clear them for sure.
Thanks
-Tirtha