1x FAS3240 or multiple FAS2240 ?


We are designing a new storage network and we are faced with a dilemna: choosing between a single FAS3240 or multiple FAS2240.

We already decided to use aggregates of 120 disks (5 DS2246 with 600GB SAS drives), and initial setup will include 2 of those (10 diskshelves).

Now we have to decide if we go for a FAS3240 (that on paper could old 5 of these aggregates), or go for multiple FAS2240 (1 FAS2240 per aggregate)

The only drawback of the FAS2240 we have identified is that's it's either FC or Ethernet, meaning we won't be able to mix our virtual environment (vmware/NFS) & SQL (physical servers/FC)

From a cost perspective, surprisingly, both solutions are equivalent (we have a pretty good deal with NetApp).

From a performance & risk perspective, I'd prefer the horizontal scalability of multiple FAS2240.

From a management/flexibility perspective, the team currently operating our FAS3210 and our FAS3240 MetroCluster says they'd prefer to go for a single FAS3240.

Before flipping a coin, has anyone some real-life experience of managing multiple "small" SAN again a bigger one ? Or additional good arguments for one solution or the other ?

Thanks !


Re: 1x FAS3240 or multiple FAS2240 ?

Hi Stéphane,

It is a tough call in my opinion.

Multiple systems can be more 'resilient', as you are not keeping all your eggs in one basket. However managing them could be a nightmare, especially if you have many volumes, LUNs, hosts, etc. - getting one's head around where is what can be really tricky! (neat naming conventions & clear documentation is key)

On FAS2240 you can actually mix IP over embedded ports (4x 1GbE per head) with FC on the mezzanine - the only thing you can't have, is a mixture of FC with 10GbE (both cards use the same slot).



Re: 1x FAS3240 or multiple FAS2240 ?

The 2240 you max out at 144 disks (so you're almost buying a maxed out box)

But with the 2240, you can literally just turn it into a shelf and upgrade to a 3240 when you're ready, and have flexibility of doing non-disruptive firmware, data ontap upgrades, and failovers in the meantime.

I would just make sure your infastructure can perform on a single 3240 or across two 2240 controllers.

I'm leaning towards the 2240 with the easy upgrade to a 3240 down the road when a duel controller setup is an option.

Please respond back with any questions!

Re: 1x FAS3240 or multiple FAS2240 ?

I would just make sure your infastructure can perform on a single 3240 or across two 2240 controllers.

Stéphane, are you considering a single 3240 controller (non-HA) vs. several 2240 HA pairs or is this a 3240 HA pair vs several 2240 HA pairs?

We have a 3140 HA pair that we are looking to upgrade within a year and may consider multiple 2240HA pairs as well.

Re: 1x FAS3240 or multiple FAS2240 ?

I assume Cluster mode is off the table (at which point theres a whole interesting conversation about the 2240's mez card vs the single management model)

Performance wise Id be curious how your currently travelling and what your doing, a pair of 2240's is almost equivilant to a FAS3240A on benchmark but the 3240 has a bigger cache (read and write).

Assuming all the 2240's are living on the same vlans vfiler migration is pretty much a snap so you've got load balancing for growth - although with a basic 5 shelf aggregate you might find the first years capacity growth purchase is surprisingly expensive compared to a FAS3240.

What would nail it for me is the 3240 has potentially spare slots and economies of scale, the 2240 would go in pretty much maxed out so your only option for exansion is another 2240 cluster - is your vmware/nfs worlkload increasing to the point where you might consider PAM cards? how quickly is your environment likely to change oer teh life of the appliances?  I'd go for a 3240 unless it was a pretty static environment or has a good planning process, otherwise the amount of time you spend bouncing resources between aggregates and physical filers will be a pain.

Re: 1x FAS3240 or multiple FAS2240 ?


Thank you all for your answers !

I didn't specify it but the compared initial setups would be:

- 1x FAS3240 HA with 512GB Flash Cache

- 2x FAS2240 HA  with 6x100GB SSD drives using the new Flash Pools technology (1 FAS with 10GB Ethernet for our vmware/NFS environment & the second one with FC)

Using aggregates much bigger than 5 diskshelves doesn't make really sense in our setup.

With 600GB disk, each aggregate would be around 100 drives (once RAID & spare disks are removed), giving us around roughly 10,000 "physical" IOPS per aggregate (and hopefully +20/30% using Flash).

We're mostly running small servers, and our biggest servers have less than 5TB of data, so load-balancing servers among aggregates/controllers doesn't seem very difficult.

From a pure cost perspective, as I said, this was my biggest surprise : with our agreement total cost of a FAS3240 & multiple  FAS2240 are very similar.

On the graph below you can see that the FAS3240 becomes really financially interesting once filled with 20 to 25 shelves :

The main risk is regarding performance.

We currently have a 3240 MetroCluster and if I look at the performance we get and the CPU load, I seriously doubt that a FAS3240 can be used at full disk capacity in our environment.

If I consider a 3240 maxed-out regarding CPU with 15 diskshelves, then the FAS2240 becomes a true winner:

I'll confirm with NetApp that they aren't unforeseen limitations with this setup, but we're seriously aiming for the NxFAS2240 architecture.



Re: 1x FAS3240 or multiple FAS2240 ?

I think it would be important to consider your read/write ratio.  WAFL is pretty good at handling writes, and the flash cache is going to be much faster than the flash pool.

Also, you are not really getting double the performance on the system side by choosing 2xFAS2240.  Consider the system specs (via wikipedia)

FAS 3240     16 GB RAM    2 GB NVRAM         Intel L5410 64-bit quad-core 2.3 GHz (12M Cache, 2.33Ghz, 1333Mhz FSB)

FAS 2240     6 GB RAM      768 MB NVRAM     Intel 64-bit dual core 1.73 Ghz

Re: 1x FAS3240 or multiple FAS2240 ?

Our R/W ratio is somewhere around 85/15-90/10, so mostly reads !

I don't know how Flash Pool compares to Flash Cache in such case.

Regarding the system specs, I got from NetApp , the 3240 has 8GB RAM & 1GB NVRAM.

The CPU of the FAS 2240 is apparently a LC3528 (Nehalem), which is much powerful than Harpertown processors (I've seen benchmark were a 2.27GHz "Nehalem" outperforms easily a 3GHz "Core").

To do a comparison purely on capacity, a FAS3240 should be compared to 4 or 5 FAS2240, and in this case the FAS2240-based setup is clearly more powerful from a "raw CPU performance" point of view.

Anyway, the "don't put all your eggs in the one basket" is until now the winning argument in this comparison :-)

Re: 1x FAS3240 or multiple FAS2240 ?

NetApp often confuses people by providing a spec per *two* controllers.

So per *single* controller it looks like this:

- FAS3240 - 8GB RAM, 1GB NVRAM (dedicated), 1x quad-core 64-bit CPU

- FAS2240 - 6GB RAM (NVRAM uses part of it), 1x dual-core 64-bit CPU



Re: 1x FAS3240 or multiple FAS2240 ?

How does the license costs (N x 2240 vs. 1 x 3240) compare? 

What about maintenance costs when comparing multiple FAS2240 HA pair to the single FAS3240 HA pair?