BladeSystem Management Software

Onboard Administrator (OA) Stacking (linking) maximum

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Onboard Administrator (OA) Stacking (linking) maximum

John asked a question regarding stacking links.




What is the maximum number of C7000 enclosures that can be connected using the OA link ports? The enclosures are in racks that are side by side so distance would be minimal.




From Chris:




I haven’t seen a max number.  I would limit it to 4, as the max number of enclosures one would have per rack is 4.  If you want to go beyond that for management purposes, I would strongly suggest using Insight Control.  You still need to authenticate to each OA, if you were to connect directly to an OA that is stacked with other enclosures.




And from Monty, the OA Master:




The Onboard Administrator will put a warning message in the OA syslog if it detects more than seven linked enclosures, but it will permit more.  We came up with the number seven as that was the maximum number of c3000 enclosures to fill a 42U rack.


The only traffic on the enclosure links other than discovery of the adjacent enclosures is for multi-enclosure GUI clients – where all the other OA traffic to the client will traverse the enclosure links.  Since this traffic is bridged in firmware between enclosures, there is significant latency added for each additional linked enclosure – so the maximum number should be restricted based on whether the performance is acceptable.


Remember that the enclosure links will not carry client traffic to either device bays (iLOs) or interconnect management processors – that traffic will only be carried over the active OA management port in each enclosure.




Any other questions or comments?