FAS2240-2 4243 and 2246 on same loops?

[jfluharty]

Connecting a FAS2240-2 with 24 internal disks (IOM6), two 2246 shelves (IOM6), and a 4243 (IOM3) SATA shelf.  Is it possible to connect all shelves to ports 0a,0b on the controller in the same loop for MPHA or do we need to connect the 2246 shelves to port 0a, since the internal disks are on 0a also, and connect the 4243 shelf to 0b because it is IOM3.  We don't want the IOM6 modules to step down to 3G.  We would like to have MPHA if possible. 

Also note that WireGuage complains and fails when we mix the shelves on the ports or put the 4243 shelf on port 0a because the internal disks are on 0a.  In fact, the controller disables the 4243 shelf when we connect it to port 0a.  See attached jpg.

Thanks

[radek_kubka]

Well, interesting - the 2240 slideware was saying that intermixing 4243 & 2246 shelves in the same stack is supported (which is different from other systems).

Regards,
Radek

[scottgelb]

likely because there are only 2x SAS ports on the 2240.  I saw something about IOM6 coming out for DS4243 (DS4246) down the road but don't know if still happening.

[radek_kubka]

I've seen that too on a slide deck for FAS2220 - allegedly you can mix all combos, i.e. DS2246, DS4243 & DS4246 in the same stack.

[aborzenkov]

Yes, you can mix shelves in this case. I believe the latest wireguage 2.1.1-16032012.1324 should be fixed to not complain on FAS2240, but I cannot find any changelog.

Thanks to Aaron, here is readme for the latest WireGauge:

WireGauge 2.1.1
---------------
  * False warning when IOM3 and IOM6 modules are mixed in the same stack for Vespa platform is resolved.

[kingslec]

Wire-gauge still prompts if both systems are on the same stack, So in answer to this I don't think they can be mixed all DS2246 shelves connected on one stack and the rest on the other this might leave you with a single "pathed" disk configuration

[radek_kubka]

I thought Wiregauge has been discontinued & replaced with Config Advisor?

From my perspective, intermixing SAS shelves has been one of the most annoying & greyest areas over the past two years - a truly moving target with conflicting messages from different resources.

This is what I just discovered in the latest Storage Subsystem FAQ:

CAN DS2246, DS4246 AND DS4243 BE MIXED IN THE SAME STACK?

DS224, DS4246 & DS4243 can be mixed into the same stack. However, when going from IOM3 to IOM6, you can’t have more than one transition.

The wording was far more ambiguous in previous versions of this document though (something like "more than one cross-over point is supported, but not recommended")

This isn't brilliant news for many existing customers, as DS4243 SAS shelves are EOL - so you need DS2246 for more SAS disks, full stop. Then adding SATA disks to the same stack may prove impossible...

[HENRYPAN2]

Yes Radek,

Config Advisor is the new name + new version from the old Wiregauge:>)

My personal view is try to Not mix DS4243 with DS4246 shelve unless you have to.

I got performance hit when I tried the mix 3 years ago.

Yes. This config "is supported, but not recommended"

That's part of the reason, I swap from purchase to lease just to keep up with the fast technology improvement:>)

Cheers

Henry

[aborzenkov]

Old wiregauge may not know about new rules.

[HENRYPAN2]

Ha-ha aborzenkov ,

The new Config Advisor know the new rules:>)

Cheers

Henry

[kingslec]

Yeah the New Config Advisor knows the rules sample below from 2 different systems

DS4243 and DS4246 below the systems had real performance degradation on this systems

DS2246 and DS4243 below

Kingsley Chibundu

Professional Services

West Africa

NetApp

+234 7032551678

kingsley.chibundu@netapp.com<mailto:kingsley.chibundu@netapp.com>

Web: www.netapp.com<http://www.netapp.com/>

[scottgelb]

Config advisor is a good guideline but there are many other checks that should...need to be done.  Checking failover groups for example, network, testing storage failover on the system, lif migration (do all interfaces work...lit up isn't always the best test). 

[bbjholcomb]

I believe if you have 3 and 6 gig connection on one connection they will slow down to 3 gig.

I believe NetApp best practice is not mix SATA and SCSI on the same controller, increases the likelihood of more back to back CPs.

[scottgelb]

The speed will drop to 3Gb. But 4 lanes so 12G and with MPHA 24G on 2 paths. I don't think a bottleneck for most controllers.