Beginners question Raid Card & SM EL2 backplane

Rand__

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Mar 6, 2014
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Have not been using raid cards in at least a decade (thanks to zfs) so I have no clue re these.

I have a SAS3-EL2 backplane, some nice SAS SSDs that can do dual port and Lenovo 930-8i's.

For ZFS i simply used 2 HBAs and got multipathing enabled without issues, but can I do the same with the Raid Controllers?
Can Megaraid span a raid over two controllers/all drives?
Or is that actually a Raid limitation i never was aware off?

(O/c I can simply use the drives with a single controller, but I have 4 of the 930s collecting dust so why not use them) ;)

Edit: I assume (and current reading supports it) that this will not work - so extra question:

How to use SAS multipath capabilities with Raid Controllers?
 

WeekendWarrior

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Apr 2, 2015
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I've wondered the same thing about the EL2 backplanes and controllers (although not particular to Megaraid). Will watch to see what comments arise on this subject.
 

abq

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May 23, 2015
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Ditto, want to learn more about dual path SAS & diy implementations.
 

T_Minus

Build. Break. Fix. Repeat
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There's an older post I asked about this, and I believe it was determined there's no "cheap" off the shelf way to do this.
 

Rand__

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Mar 6, 2014
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There's an older post I asked about this, and I believe it was determined there's no "cheap" off the shelf way to do this.
Some search terms would be nice, its not as if you hardly ever said a word;)
Or a rought posting ime estimate?;)
 

Rand__

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So the Megaraid manual basically says the adapter will do multipathing itself, but only for redundancy, not necessarily performance increase
No comment re spanning a single raid drive over two controllers...
 
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Rand__

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Just to finish this up - contacted Supermicro.
They said no go, using two raid controllers on the same expander backplane needs zoning support on the backplane so it properly can separate different drives to different controllers, else you have all sorts of issues (which i've seen when i tested it).
 
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