As far as I know, there is no FAS 2440 model. Is your model a 2240?
You will need at least 3 drives for the second controller. I would suggest you allocate three of your 1TB drives for the second controller (one raid4 aggr composed of 2x1TB drives and one spare 1TB drive).
Your rgs should be balanced (in number of disks), so 19-4-19-4 is probably not a good idea. Also, I doubt Ontap will allow a rg size 19 raid4 group. Personally, to maximize capacity, I would create two aggregates on the primary controller - the first aggr composed of 2 raid4 rgs of 11x2TB drives each (leaves 2 spare 2TB drives in primary controller), second aggr composed of 2 raid4 rgs of 10x1TB drives each (leaves 1 spare 1TB drive in primary controller). You could also combine all four rgs into one large aggregate, subject to the max aggregate size of your filer model (and use rg size 11, but have only 10 in the 1TB rgs.)
Also... personally, I prefer to use the power of two controllers, therefore I would put the 2TB shelf on one controller and the 1TB shelf on the other controller. But that's just me.
Have I sufficiently confused you yet? If so, please feel free to ask for clarification.
Of course, you are right, I have a FAS 2240. Thanks for pointing this out.
I think I understood your suggestions and they sound good to me. I did not know I had to give some disks to the second controller. Does it need an extra spare drive or could it use the spares from the primary controller?
If I would go for your two Controller solution would this mean I have to change the cabling or is this all done in software?
I was assuming you had a dual-controller 2240 and it sounds like you do. I don't know what your SAN background is, but if you come from HP or EMC background, in general their controllers are more homogeneous as compared to NetApp FAS. Think of your 2240 as two separate systems that can failover to each other. So therefore, you do need a minimum of 3 disks (a 2-disk raid4 aggr and 1 spare) on the second controller (for the root volume). Each controller has their own spares, so you do need the 1 spare on the second controller.
If you want to utilize the power of both controllers (kinda like an active-active config instead of an active-passive) you do not need to change the cabling. The disks can be moved around through software ownership.
If you will have further questions, please mention the protocols you will be using (FC, iSCSI, CIFS or NFS) as that would be helpful information too.
What kind of disk do you have? 2TB makes me think SATA which in 7 mode has a maximum raidsize of 7 disk for RAID4 (1 parity and 6 data)
RAIDDP lets you go to 20 (which gets you up to 9 data per parity disk)
Next question is your workflows...do you need one filesysem thats potentially visible by everyone? In which case I'd put all the disks but 3 (1 parity 1 Data and 1 Spare) on one controller as one 64 bit aggregate. If you need two filesystems or the portability of virtual machins (vfilers) then I'd still be tempted to use one controller with the other one as a backup, but then splitting the disks and filessytems between controllers would be possible and may make more sense.
Netapp gear is very configurable up to a point, you just need to work out what you want and then the best way of doing it kinda falls out
I have BSATA disks. I want to use CIFS and NFS with NTFS permissions. The FAS is cvonnected to the normal Ethernet network. No SAN.
I am coming from a Sun X4500 with 48x500 GB disks, using zfs. I have about 400 Filesystems there and it is really easy to configure compared to a FAS2240. We use the X4500 mainly as a storage System for home and Project Folders. For the FAS, I think I will use much less volumes, maybe two or three.
For the aggregate configuration so far I like the two Controller active with RAIDDP solution best at the moment. Seems to be the most efficient solution regarding space and security.
Good idea on the raid-dp... you really wouldn't have increased your capacity more with raid-4 and you'll be better protected with the raid-dp. As andrewgeorge mentioned above, the rg size limit of raid-4 SATA is 7 drives (I apologize for missing that but I really don't do raid-4 at all). In your case, with raid-dp, you can do rg size 12, with rg0 having 12 disks and rg1 having 11 disks, leaving you with 1 spare.