We have a VNXe3200 with 19 x 10k RPM 900 GB SAS Disk:-

4 already used by the OS

15 x Disk is for RAID Data.

We want to leave at least 1 x spare SAS Disk

what is the best raid group 10 configuration for the storage pool??

If I do a 2 x (3 + 3) ~ 12 Disk, that would leave 3 spare.

Is there a better Raid Group configuration???

Is it ok to do a (3 + 3) + (4 + 4) Raid 10 with 14 disk and leaving 1 spare??

But I am not sure if the mixing of (3+3) + (4+4) would have any performance issue.

Thanks for any advise and comment.

Also, we are told by our Vendor for NOT to include those 4 x OS disk into any Raid Configuration, why is that a best practise of wasting the 4 x OS disk that still has 80% capacity free???