Port Persistent Disabled?

[Derek C]

We got a C Class Blade with 2x Brocade switches installed.

We have newly installed a blade to it and assigned a LUN (from EVA6000) to it. Everything works fine. However when I am looking at the port on the brocade switch, I find that both switches have that particular port set to 'persisten disabled'

Funny enough even it's said to be disabled, my host can still see the SAN without any problem.

We got 12 additional license installed so licensing is not an issue. I am wondering if the switch by DEFAULT is set the port to be "persistent disabled"?


thansk,

Derek

[Derek C]

Forgot to mentioned, when I said the host can see the SAN LUN, I mean it can see all the path without any problem.

I have tried to set the port to be Persisten Enabled on one of the switch, it has no effect on the host at all.

Attached is the screenshot of the Persistent Disabled port.


Derek

[krusty]

Hi Derek,

The "port persistant disable" on a Brocade SAN switch is a security feature they added several years ago. Back in the day, a best practice was to disable all ports that were not connected to a device. However, if you rebooted the switch, the ports came online again. So, Brocade came up with the "port persistant disable" to address this.

Now, as for your host seeing a LUN from the EVA via this port, my best guess is you have the ports mixed up somehow. They are mapped to the respective ports in the rear. i.e slots 7 & 8 map to port 23 (second from right) on the physical switch. The mapping can me changed from the default, however. Double check your cabling.

Cheers,

Curt

[PP BIJU KRISHNAN]

derek,

can u post the switchshow from the mentioned switch. It seems like someone has swapped the ports without informing you.

A simple way to check this is by identifying the port number from the HBA utility. this can clear our doubts.

[Derek C]

Hi guys,

Thanks for reply. First of all, I don't believe that I mixed up the port, because the port I am talking about is the internal port between the blade switch and the blade itself. When I shutdown the blade (Lucky it's not in production yet), i can clearly see the port go offline, i.e. the 7th blade connect to the port 7.

I did a simple test:
- In my configuration, there is 2x blade switch, Path to the LUN is 4 (2 from each switch). Both was set to persistent disabled by the switch. I check the command line interface using portshow, same result.

- I change the port on Switch01 to be persistent enabled, NO EFFECT.

- Then I shutdown the blade, change the port back to persisten disabled on Switch01.

- I turn back on the blade, and guess what, it now lost the first 2 path (which that path is the path that go through Switch01). And the switch show a orange light on the web console.


- So basically if I have manually "persistent enabled" a port, if I do "Persisten disabled" that port again, then it will really be disabled. I believe that it's a bug? So at the end I just persistent Enabled both port.


thanks!

Derek

[krusty]

HI Derek,

I think I see the issue. When you issue the command throught the CLUI or check the box in the GUI, it takes affect AFTER the next time the port goes offline. SO, a reboot does that in effect. If you set the port to pesistant disabled and THEN disable the port, I think you would see it it disabled.

Cheers,

Curt

[Derek C]

I thought the only different between persistent disable and disable is htat persistent disable will keep the port disabled after the switch reboot?


And I find that you cannot disable a port AFTER you have set that to persistent disabled, as the GUI on it is greyed out, please check the screenshot :)

btw, On the blade Web Tools, if I manually set the port to persistent disabled, it will flash orange light regardless if the host is turn on or not. But previously when I first look at it (when the port show as persistent disabled) the port is green.


Anyway I am not too concern about it now, I just persistent enable both port.


thanks,

Derek

But