topic Re: FAS3210C (8.1.1) and DS4243 - RAID Group Size and Hot Spares? in ONTAP Hardware

FAS3210C (8.1.1) and DS4243 - RAID Group Size and Hot Spares?

dartfordbc — Thu, 05 Jun 2025 06:17:36 GMT

We have just connected an additional shelf of 600GB 15kSAS DS4243.

Currently my controller which I'm adding the shelf to has 2 x RG (16 Disks) - RG0 has 16 disk and RG1 has 6 disks. That leaves 2 spare

What is the best option about adding this new shelf? Do I leave the RG at 16 disks? If I do to give best performance and balance I have to use 26 disks which leaves only 1 spare.

Do I increase the RG size to 23 and use 24 disks so the RG are balanced?

Thanks in advanced!

Re: FAS3210C (8.1.1) and DS4243 - RAID Group Size and Hot Spares?

radek_kubka — Thu, 11 Oct 2012 11:51:23 GMT

Hi,

It is a dual-controller system, right?

Are you adding all 24 new disks to one of the controllers only? If you don't tweak anything, then you will end up wit a pretty neat setup IMHO:

- RG0 - 16 disks (no change)

- RG1 - 16 disks (6 old + 10 new)

- RG2 - 14 disks (all new)

- 2 hot-spares

Nothing wrong about this in my view.

Regards,

Radek

Re: FAS3210C (8.1.1) and DS4243 - RAID Group Size and Hot Spares?

dartfordbc — Thu, 11 Oct 2012 12:11:21 GMT

That's correct, a dual controller system.

Yes I'm adding all 24 new disks to one of the controllers only.

Thanks for your help, I wanted to check it was right as the warning message about not being balanced was a little off putting!.

Thanks again.

Re: FAS3210C (8.1.1) and DS4243 - RAID Group Size and Hot Spares?

radek_kubka — Thu, 11 Oct 2012 12:25:36 GMT

RAID groups are very unbalanced now (16+6), but should be fine after adding more disks (16+16+14).