3750 Stack and iSCSI question

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Feb 25th, 2008
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I have two 3750G-24T switches sitting between a couple of servers and a Lefthand iSCSI SAN. Each server and all of the SAN modules have two NICs (one connected to each switch). Is it better to have the switches stacked or should I put them in a cluster? Or both stack and cluster? Or is there a better way to setup the switches for an iSCSI SAN? Which method provides for a better failover?


Right now the switches are in a stack. Over the weekend, one of the switches had a problem and all of my servers loss access to the SAN. Is there some sort of delay when a stacked switch fails? I had to reboot both switches to regain connectivity to the SAN.


Thanks for any and all replies.

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Joseph W. Doherty Mon, 02/25/2008 - 20:15
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You didn't mention whether you're doing L2 or L3 via the 3750s. L3 is controlled by just one elected stack member, failure of such an active master might cause one of the slowest recoveries, but likely any stack member loss might cause some interruption.


If all ports on the stacked switches are multi-homed to all the connected hosts, there might be advantages breaking the stack. For instance, not having the switches have to contend with all the traffic placed on the stack ring (according to the improvements made on the 3750-E, the original 3750 puts all traffic going across the member switch on the ring).

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