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 Post subject: F400 cabling Daisy Chained
PostPosted: Thu Mar 21, 2013 1:37 am 

Joined: Tue Mar 19, 2013 1:28 am
Posts: 3
Hello,

i have a F400 with 2 Controller nodes and 2 disk enclosures. Has anyone a cabling guide how to connect the disk enclosures to the controllers in daisy chained mode?

Thank you


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 Post subject: Re: F400 cabling Daisy Chained
PostPosted: Mon May 20, 2013 3:25 pm 

Joined: Thu Sep 13, 2012 10:49 am
Posts: 5
Can I ask why you would want to daisy chain if you only have 2 shelves?
I would actually recommend you stay away from daisy chaining it caused us some grief.
Our config was a little larger, we had a couple of shelves with SSD and 15k FC disks and under certain load conditions we would have select spindles with high latency which took a very very long time to diagnose, turned out that the half of the disks that were 'owned' by the controller using the daisy chained path got latency issues, which turns out to be a known 'issue due to design'.
In the end we upped from 2 to 4 nodes and reconfigured to drop all daisy chaining.

Hope it helps.

If you still want to do daisy chaining, then in a nutshell (this is just for illustration only)
But:
Node0 access shelf 1 directly and shelf 2 via shelf 1
Node1 access shelf 2 directly and shelf 1 via shelf 2

I'll have to dig out the docs if you really still want it :)


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 Post subject: Re: F400 cabling Daisy Chained
PostPosted: Wed May 22, 2013 5:02 pm 
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Joined: Tue Aug 18, 2009 10:35 pm
Posts: 1219
Location: Dallas, Texas
I concur, if you have the back end ports to support direct connect to shelves, that is best.

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Richard Siemers
The views and opinions expressed are my own and do not necessarily reflect those of my employer.


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