It depends on the version of OnTap you are running. Prior to 7.3 it was based on raw size. As of 7.3 it's cooked size.
There's a nice chart in the 7.3 release notes under 'Storage resource management enchancements' showing all this.
On Mon, Dec 01, 2008 at 08:25:01PM +0000, James Beal wrote:
On 1 Dec 2008, at 20:14, Bill Holland wrote:
It wouldn't be a matter of the number of disks in a shelf, but the raid group size and number of disks in the aggregate. Even if it would work, you would end up with wasted disk space as the largest aggregate you can have is 16TB. With 320GB disks, that would be roughly 56 disks, with 1TB disks, it would only be 16. So, if you have more than 16 disks in your current aggrate, you would exceed your max aggregate capacity after 16 1TB disks if the filer were to see them as 1TB disks.
As an aside isn't it the maximum size of the aggregate the cooked size rather than the raw, so isn't it around 19 disks ( there is an option which I am not sure is documented to raise the maximum group size ).
This is from a netapp pre-sales person.
Storage system
Minimum group size
Maximum group size
Default group size
All storage systems (with SATA disks)
3
16
14
All storage systems (with FC disks)
3
28
16
1TB SATA = 10,615GB ? max 19 disks per aggregate based on 1 spare and two RAID sets of 8+2 and 7+2 This means you can get about 105TB of real space out of a cabinet of 1TB drives versus about 85TB for the next drive size down, 750GB drives
The option you suggested of a single RAID set per aggregate is not supported as this would require 19 disks in the RAID set. 12,030GB = max 19 disks ? 1 x 17+2 (unsupported)