Fibre Channel (SAN)

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New Contributor
Posts: 3
Registered: ‎12-03-2015
Accepted Solution

tim_txcrd_z_vc counters fileds

Hello guys,

 

Each line of tim_txcrd_z_vc counter has 4 columns.

I understand what tim_txcrd_z_vc counter shows in general but what exactly each column does represent?

I couldn't find any information about it.

 

tim_txcrd_z 1158786 Time TX Credit Zero (2.5Us ticks)
tim_txcrd_z_vc 0- 3: 0 0 1158786 0
tim_txcrd_z_vc 4- 7: 0 0 0 0
tim_txcrd_z_vc 8-11: 0 0 0 0
tim_txcrd_z_vc 12-15: 0 0 0 0

 

 

Contributor
Posts: 34
Registered: ‎05-12-2013

Re: tim_txcrd_z_vc counters fileds

Read about virtual channels. :)
New Contributor
Posts: 3
Registered: ‎12-03-2015

Re: tim_txcrd_z_vc counters fileds

[ Edited ]

Thank you for reply but this is not what i meant. I was talking about columns, not lines.

 

So what exactly each number for virtual channels 0-3 stands for?

tim_txcrd_z_vc 0- 3: 0 0 1158786 0

 

I have assumption that tim_txcrd_z for vc 2 is 1158786. Is that correct or not?

 

Occasional Contributor
Posts: 10
Registered: ‎06-01-2016

Re: tim_txcrd_z_vc counters fileds

Hi.

The number in each column shows the number of times when the buffercredits have reached zero and stayed there for 2.5 microsec. If the delay gets increased, >500ms, the counter ”er_c3_timeout” is increased.

 

The set up for this line:

 

tim_txcrd_z_vc 0- 3: 0 0 1158786 0

 

Meaning:

Value: tim_txcrd_z_vc

Channels: 0- 3:

Value for each virtual channel:

Channel 0:        Channel 1:            Channel 2:            Channel: 3

0                       0                           1158786                0

 

So this means that your channel 2 (Medium priority channel) is sending data.

But this does not necessary mean that you have to few buffers allocated to the port.

Before a certain fw version, can´t remember which one, the counter increased even though there was no data in the queue which made the counter to keep going “without” reason.

 

I hope this helps.

Ulf

 

New Contributor
Posts: 3
Registered: ‎12-03-2015

Re: tim_txcrd_z_vc counters fileds

[ Edited ]

Yes, thank you. It's clear now. :smileyhappy:

Althught I thought that concept of Virtual channels is applicable to ISL links only and this is Node port.

Frequent Contributor
Posts: 132
Registered: ‎02-05-2014

Re: tim_txcrd_z_vc counters fileds


UlfJ wrote:

Hi.

The number in each column shows the number of times when the buffercredits have reached zero and stayed there for 2.5 microsec. If the delay gets increased, >500ms, the counter ”er_c3_timeout” is increased.

....

I hope this helps.

Ulf

 


That is incorrect. The counter wil increase if at the 2.5microsecond interval the value of tx_credits is zero. The ASIC wil look every 2.5ms and if at that exact moment in time the value is zero the counter is increased by one. It does not have to stay there for 2.5ms.

 

Also the 500ms timeout-value is related to the edge-hold-time which differs per platform and FOS level and also depends how it is configured by the san administrator. Read more here

Kind regards,
Erwin van Londen
Former Brocade Distinguished Architect
http://www.erwinvanlonden.net The Fibre Channel blog


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