Subscribe

Simulator disk limitation

Hi,

I was wondering if NetApp will ever revisit the disk size or disk quantity limitation for the simulator.  Right now, I feel that the number of disks and the size is very limiting on what you can do with it, especially if you want to play around with vmware ESX and windows host snapdrive (6.3 which supports NFS) and other features.  It would be nice if we could bump up the total size to something more useful in a test/learning environment to something greater than 50gb (i think) total limit of useable space, to say 150gb.

Re: Simulator disk limitation

Daniel -

It's not likely !

In the old days there were 10g disks for the sim, but NetApp found that folks were using the sim in production situations. Hence, the current limitations

of using 1g simulated drives and only 28 simulated disks.

Given that you're qouting a 50g size, I'd guess you've already found the hack to change maxdisks to 56. But you won't be able to do cluster failovers.

I don't find it to be a limitation for snapdrive or any other software you want to use with the sim. Just create smaller LUNs.

At your service,

Eugene Kashpureff

Re: Simulator disk limitation

I concur. For any type of array mirroring or snaping, or even SRM testing it's really very very limited. No such thing on celerra sim.

Re: Simulator disk limitation

Hi folks,

So I'm wondering if the people who are having issues with the current disk limitations could write up a bit more detail about what they are trying to do and can't due to the limits:

What use cases for the simulator are eliminated or made much more difficult due to the limitations?

What capacity limits would be sufficient?

If you needed to choose, would it be better to allow more disks or larger capacity disks?

What would be a good mechanism to keep simulators from being used for production?

If we can get enough useful feedback, then it'll be easier to make a case for changes in future versions of the simulator.

Thanks and take care,

Miroslav

Re: Simulator disk limitation

Miroslav -

I haven't seen any cases where the simulator can't be implemented to do test/lab/demos of NetApp technology.

We've been using simulators very extensively over the past two years. We use simulators for classroom labs for

many of the NetApp classes we teach. We implement Snapmirror, Snapvault, SMO, SME, SMSQL, SMVI,

and Operations Mgr. in VM environments using the simulator...

At your service,

Eugene Kashpureff

Re: Simulator disk limitation

I have often wondered why NetApp would not release an more unlimited version of this software, maybe with a fee? I see HP making money with the LeftHand software to create very rudimentary DR sites...

Re: Simulator disk limitation

A great example is SRM proof of concept.

Trying to create a scenario which demonstrates NetApp ONTAP, with SRM on VirtualCenter, Failing over and Failing back (multi sync volumes) using iSCSI and NFS (so block and file). With a demonstration of OTV from Cisco making it close to a real world turnkey architecture (IE - show me the money and this can be rolled out asap).

The problem of course is space. Getting a 3 AD server heirachy, with SQL, file servers and myriad other test VM's to make the simulation as real as possible just won't fit on 50G. Even deduped. Then having to tear that down to do more snapmirror testing or such means that I have to keep multiple sims archived and bring them back online everytime a new question is raised or new change to the architecture is planned. Add to this, Win2k3 and Win2k8 and it's bloated requirements means nothing really fits. And then do you want to use VSC to test a few things out? Well make another sim then....

Not saying an unlimited license be given, but having the option to size to say 36GB disks (for RAID sets to be even closer to RL comparisons) and allowing up to say 360G means more options to make cached cross site volumes, LUNs and shares within the same sim to better emulate the actual real world designs and possibilites.

I can see the challenge NetApp has with such a robust design being surreptitiously used in production, but at some point the lack of options to customers to better mirror environments and features for testing holds back the uptake on NetApps technology.

Re: Simulator disk limitation

Srnicholls, great write-up.

A 28GB limit for active/active virtual sims is good if you want to play around with NFS and CIFS and other basic configurations for testing or to spruce up your skillset while not playing around on your production systems, but for all the other nifty software/tools, VSC, SDfor Windows, ESX datastores, SMVI, etc.  I really feel that it's impossible to integrate and test on two active/active sims with a limit of 28GB.  To be honest, I just fired up the simulator yesterday and still trying to do the basics, which 28GB should be sufficient, but if i wanted to do all the other cool stuff then i think 28G is limiting.  Like Srnicholls stated, I find it very difficult to manage multiple sims for different test/config/POC scenarios.

Another question, I didn't see a sim license for SD for Windows.  Did I overlook it or is it not included.

What use cases for the simulator are eliminated or made much more difficult due to the limitations? What Srnicholls stated.

What capacity limits would be sufficient?  What Srnicholls stated or 200~300GB

If you needed to choose, would it be better to allow more disks or larger capacity disks? I'm not sure if it really matters since it's all virtual, but i would lean with more disks.

What would be a good mechanism to keep simulators from being used for production?

1.  You can't call in for support.

2.  In terms of performance, it's dependent on the physical machine the sim is hosted on.

3.  Even at 300GB, i find it hard to actually use it in a normal production environment.  People are storing way more data now then they did in the past.

Re: Simulator disk limitation

To me the limiting factor is the 2m NVRAM backing that the sim has, trying to copy anything to the sim over CIFS/iSCSI is painfully slow. Granted, I run the SIM inside a VM, but hours to copy off a couple of gigabyte to a CIFS share seems a little pokey to me. I tried to use it once to make a virtual machine with iSCSI, gave up with that real quick. Mainly all I've been able to use it for is verifying command syntax for things I don't like to do on the real hardware without knowing the end result (and since most of my storage is FC attached, I don't have a lot of things to verify against on the sim).

Re: Simulator disk limitation

Ah, NVRAM! - well that also makes more sense now - since a 15G VM copy over NFS takes 4+ hours. Add this to the list of 'Yes, please' on the next Sim.

Why cripple the performance of something that is used by (and accessible only to) current customers, and may influence their view of the software in the long term?

I can only assume that the Sim development resources are pretty thin, and thus why it's not under constant update (c'mon, I'd love a VAAI enabled 8.0.1 sim!).

Hope the higher ups see that releasing a better simulator will only increase the core competencies and architectural designs of the community that work with and endorse NetApp products.