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Frequent Contributor
Posts: 107
Registered: ‎04-05-2011
Accepted Solution

nscamshow issue

Hello!


Hope you guys could help me with following weird scenario


I have a fabric with several switches, no VFID, no SCC/DCC are configured, fdd is in default.


fabric topology is likely belhow(there are other switches in the fabric, they are removed because I think it is not relevant to the problem, for now):


SW20 <TRUNK> SW3 <TRUNK>SW52


SW20 - have my initiators IBM AIX PowerSeries (NPIV)
SW3 - is the core
SW52 - have my target (18 tape drives)

When i issue nscamshow from SW20, the output relate to domain 52 is like below:
Switch entry for 52
state rev owner cap_available
unknown v731 0xfffc14 1
Device list: count 0
No entry is found!

when i run nscamshow from any other switch in the fabric i have the following output:
Switch entry for 52
state rev owner cap_available
known v731 0xfffc04 1
Device list: count 18

Seems that SW20 is not receiving the device's fabric logins.

any thoughts ?

SW20 and SW3 is FOS 6.4.3 (brocade B-48000) and SW52 is 7.3.1 (DCX-4)

Valued Contributor
Posts: 539
Registered: ‎03-20-2011

Re: nscamshow issue

[ Edited ]

Do you have actual connectivity between the AIX servers and the tapes?

 

If not... I've been to the situation like this, even a couple of times. Every time this happened when I had to perform some extraordinary maintenance on the affected switch inlcuding switchcfgpersistentdisable, full power reset and switchcfgpersistentenable at the end of the maintenance procedure. After that, the switch was able to join the fabric so that on both ends I've seen all the switches listed in the fabricshow.

 

But the devices were not able to see each other, and here is what I mean:

- All the devices in the affected switch were connected fine (in my topology I have initiators and targets all over the fabric);

- All the devices in the rest of the fabric were connected fine;

- None of the initiators attached to the affected switch could see anything in the rest of the fabric;

- None of the initiators in the rest of the fabric were able to see targets in the affected switch.

 

I noticed that some switch entries in the nscamshow output have status "unknown" while some others have status "known" - exactly like in your output. I used to call this issue "name server segmentation".

 

In order to fix the issue, I had to perform switchdisable/switchenable of the affected switch one more time.

 

When the issue was cleared, all the nscamshow switch entries were reported as "known".

Frequent Contributor
Posts: 107
Registered: ‎04-05-2011

Re: nscamshow issue

Hello Alexey!

 

Thanks for your reply!

 

Actually, there is no working connection to SW52.

 

When you say affected switch, you mean the switch that have the unknown status (SW20) or the switch that is not seen (SW52) ? I ask this because on all other switches in the fabric, the SW52 can be seen via nscamshow.

Valued Contributor
Posts: 539
Registered: ‎03-20-2011

Re: nscamshow issue

Ok, let me clarify that. In my case I had three switches, let's say SW1, SW2 and SW3, and they are all connected together like triangle, i.e. full-mesh in this case. So let's say I had to reset the power on SW1, and I call it "affected". After the maintenance and switchcfgpersistentenable, fabricshow was happily reporting all three switches in the fabric _wherever_ you launch this command. And all the E-Ports were shown online with the appropriate neighbor switch name printed in the switchshow output on _all_three_ switches. But nscamshow on SW1 was empty with two "unknown" entries for SW2 and SW3, while nscamshow on both SW2 and SW3 was showing the entries from SW3 and SW2 respectively, and mentioned an "unknown" entry for SW1. To clear the issue I had to perform switchdisable/switchenable on SW1 again.

Valued Contributor
Posts: 539
Registered: ‎03-20-2011

Re: nscamshow issue

One more point, in my case all three switches were the same model (8510-8) and running the same FOS version (7.3.1d)
Frequent Contributor
Posts: 107
Registered: ‎04-05-2011

Re: nscamshow issue

Ok! Copy that!

 

In my case, the solution can't be as simple because the switch that are presenting the sympton has several online and a disable on this may require some planning. (It only misses the SW52 in nscanshow, the other switches in the fabric are OK from it)

 

I'll look for a non disruptive manner to force the nameserver reload while in parallel plan this outage if needed. Wondering if a HAfailover would reload the nameserver....

Valued Contributor
Posts: 539
Registered: ‎03-20-2011

Re: nscamshow issue

We tried that but hafailover didn't help in my case...

How did you run into that state? Did you have any reset on the links or?.. Do you know the exact timestamp of your issue? Maybe AIX errpt started to show some messages at some specific point of time? What's seen in the switch logs around the same point of time? Do you plan to open the case about this issue? I'm interested to know any further details on this...
Frequent Contributor
Posts: 107
Registered: ‎04-05-2011

Re: nscamshow issue

 

 

I was engaged now on this case, and I'm collecting more information about this (excatly what you asked for), in parallel I requested to the SAN admin to open a ticket to Level 3. As soon as a get the answer, I'll let you know!

 

I'll  continue to hacking on this, but thanks for now!

 

 

Frequent Contributor
Posts: 141
Registered: ‎05-26-2009

Re: nscamshow issue

hmm... a nameserver inconsistency then... maybe DEFECT000513776 ?

 

Just like to know (not because of this bug): Could you both post the beginning of the switchshow (not the ports, just the part at the beginning) of your switches?

Valued Contributor
Posts: 539
Registered: ‎03-20-2011

Re: nscamshow issue

DEFECT000513776 doesn't seem to apply in my case, as all the zoning is set to NoAccess, even in the unused default FID.

 

Here we go with the switchshow:

 

1) The "affected" switch with three FIDs:

...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Principal
switchDomain: 31
switchId: fffc1f
zoning: OFF
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 128, Base Switch: No, Default Switch: Yes, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Subordinate
switchDomain: 31
switchId: fffc1f
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 33, Base Switch: No, Default Switch: No, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Subordinate
switchDomain: 31
switchId: fffc1f
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 35, Base Switch: No, Default Switch: No, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

 

2) The second switch in the fabric with three FIDs:

...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Principal
switchDomain: 32
switchId: fffc20
zoning: OFF
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 128, Base Switch: No, Default Switch: Yes, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Principal
switchDomain: 32
switchId: fffc20
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 33, Base Switch: No, Default Switch: No, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Principal
switchDomain: 32
switchId: fffc20
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 35, Base Switch: No, Default Switch: No, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

 

2) The third switch in the fabric with three FIDs:

...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Principal
switchDomain: 33
switchId: fffc21
zoning: OFF
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 128, Base Switch: No, Default Switch: Yes, Address Mode 0]
Index Slot Port Address Media Speed State Proto
...

switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Subordinate
switchDomain: 33
switchId: fffc21
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 33, Base Switch: No, Default Switch: No, Address Mode 0]
...

Index Slot Port Address Media Speed State Proto
switchType: 120.0
switchState: Online
switchMode: Native
switchRole: Subordinate
switchDomain: 33
switchId: fffc21
zoning: ON (cfg0)
switchBeacon: OFF
FC Router: OFF
HIF Mode: OFF
Allow XISL Use: OFF
LS Attributes: [FID: 35, Base Switch: No, Default Switch: No, Address Mode 0]
Index Slot Port Address Media Speed State Proto

...

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