VSvatek
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how long does vertical port failover take?

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We have couple PS4110s, PS6110s and PS6210s, all redundantly connected to 2 switches (PS6210s only have configured ETH0 on both controllers).

We need to replace one of the switches. I assume once we unplug the cables or turn off the switch, vertical failover should kick in, right?

Now the question is HOW long does actually this failover take? I've found some inconclusive information that for the 4110/6110 it might take up to a minute, with 6210 being much faster?

Basically will the be connectivity outage for the hosts connected to the arrays and if, how long?

Most EQLs currently have active controller on the switch we need to replace.

Thanks in advance

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RE: how long does vertical port failover take?

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Hello,

Vertical failover is virtually instant.  The failover time you are referring to is for entire controller failover, not the vertical port failover.

Regards,

Don

Social Media and Community Professional
#IWork4Dell
Get Support on Twitter - @dellcarespro

VSvatek
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RE: how long does vertical port failover take?

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Hello Donald,

thanks for answering the question. When vertical failover happens, the active controller doesn't change,  but the ETH0 IP address moves and the traffic flows through the passive controller. After we replace the switch and reconnect the cables, is there way to "switch" the traffic back to the active controller?

Allow me one other follow up question - how long does controller failover realistically take how long on the arrays I've mentioned?

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RE: how long does vertical port failover take?

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Hello,

Not quite.  The physical connection is passed to the active CM, from the port on the passive.  It's an electrical connection.  So the IP address doesn't really move.  If it did, the MAC address would change and all connections would have to be dropped and reconnected.  

Re: Failover.  The answer to that is:  "It depends".   While the new controllers are faster, the firmware revision is crucial, the number of iSCSI connections, members in the pool, load on pool/member, etc...

All of these contribute to the failover time.

On a light load, current firmware, newest CM?   I've seen failover complete in less than 15 seconds.  

The last few years the failover process has been improved and streamlined.  Years ago the process required a complete reboot, now in effect the passive grabs the disks, see RAIDset, takes over, then connections can login again.  

Regards,

Don

Social Media and Community Professional
#IWork4Dell
Get Support on Twitter - @dellcarespro

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VSvatek
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RE: how long does vertical port failover take?

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Thanks for the answers, have a nice day.

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RE: how long does vertical port failover take?

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Thank you, I will!   Nice sunny, cool weather has settled in for the week. Smiley Happy

I'm glad I was able to help you.

Best regards,

Don

Social Media and Community Professional
#IWork4Dell
Get Support on Twitter - @dellcarespro

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