topic Re: Increasing Aggregate with large disk sizes in ONTAP Discussions

Increasing Aggregate with large disk sizes

GUVNIJJAR — Thu, 05 Jun 2025 06:42:20 GMT

I have an aggregate which is nearly full, it has 2 raid groups currently, one with 16 disks, and the other with 14 disks, the RAID group size is set to 16 disks for this aggregate. I want to increase the disk space on this aggregate and have some spare disks which i can add to the aggregate, but the spare disks are of a larger size than the current ones used. So if i add 5 disks to this aggregate with a larger size would they create a new 3rd raid group inthis aggregate, or would it fill up the second raid group to 16, and then rest in a 3rd raid group.

Re: Increasing Aggregate with large disk sizes

aborzenkov — Fri, 28 Oct 2011 11:45:07 GMT

As is two disk swill be added to RG with 14 disks. First set rg size to 14 and then add disks – they will go to new RG. Setting RG size does not affect existing raid groups.

Re: Increasing Aggregate with large disk sizes

scottgelb — Fri, 28 Oct 2011 11:55:34 GMT

Ideally don't mix drive sizes but if you have to the new raid group is a good idea... For optimal performance the best practice is to keep all raid groups the same size or within 1 drive and the same drive type (but in reality this doesn't always work out). It is supported to do what you listed...change raid size like mentioned before the aggr add then change back to 16 after, or alternatively on aggr add you can specify "-g new" to force a new raid group on the additional 5 disks to get 3D+2P added to the aggr whithout modifying the rg size with the same effect.