austin-t
2 Iron

Vertical port failover behaviour

Hi, 

Can someone please explain the correct port failover behaviour please?

Here's the scenario: First iSCSI switch is rebooted/or fails: The active and standby CM now both have connections to the single remaining iSCSI switch i.e. vertical port failover. Great so far.

Q: Once the first iSCSI switch comes back on line should the standby CM port failback to the first switch?

Currently it doesn't fail back, is the correct? If the second switch is now rebooted or fails the array will lose connectivity to the hosts.

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5 Replies

RE: Vertical port failover behaviour

Hello,

When the 2nd switch is rebooted it should fail back to the first switch at that time.  It does not fail back when the first switch comes back up automatically.

I would check the cabling and make sure the first switch was fully booted before rebooting the 2nd switch.

Regards,

Don

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austin-t
2 Iron

RE: Vertical port failover behaviour

Thanks Don,

OK, I rebooted the second switch to test this. The two active switch ports on the bottom switch (In vertical port failover) flipped to the top switch, so no data loss but the array is still in vertical failover even after both switches are operational.

The only way to correct this is to pull a cable on the standby controller which then corrects the situation, the end result being that the live ETH ports are on the Active CM.

I would have thought that the EQL has the intelligence to make sure that live ETHs were on the active CM. Especially as LLDP is advertising the switch name and port.

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RE: Vertical port failover behaviour

Since it's only the connector being used there's really no need to failback.  

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austin-t
2 Iron

RE: Vertical port failover behaviour

Hi Don,

Perhaps I should have stated from the start that this is a PS6210 with two ports per CM.

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RE: Vertical port failover behaviour

That's ok, same principle.   That active CM can use either physical port, and switch back and forth w/o a problem.

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