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Occasional Contributor
Posts: 9
Registered: ‎10-08-2013

High Time BB_Credit Zero on ISL Downstream / trunkmaster

Hi All,

I have an ISLof 4 lines, and all seems well.

I was investigating the BB_credit zero buffer, if we should increase because of a high rate of Time BB_Credit Zero.

On a downstream port i see sometimes a rate of 132 / 128 / 32 % and that is rather high

The other 3 ports dont have such a high rate, just normal what you should expect.

I dont see discarded C3 frames or bad os or enc out errors.....but i'm wondering why i have such a high BB_credit zero rate ....

ANyone any suggestions to help me in one or the other direction ?

Thanks a lot.

Cheers,

Henrico Lebbink

External Moderator
Posts: 4,854
Registered: ‎02-23-2004

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

this can have many reason, i.e. distance, Speed Port settings etc. ?

TechHelp24
Occasional Contributor
Posts: 9
Registered: ‎10-08-2013

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

The distance is < 10 km and all port have 8Gb / fillword 3 and LE. The ports are divided on 2 different blades, e.g. 2/0, 2/1, 8/0 en 8/1

External Moderator
Posts: 4,854
Registered: ‎02-23-2004

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

--->>>I have an ISLof 4 lines,.....

are this the port that for the ISL to -> The ports are divided on 2 different blades, e.g. 2/0, 2/1, 8/0 en 8/1

--->>>On a downstream port.....

when you spoken from "downstream" you have formed a Trunk.

how is this trunk formed ? --->>> 2/0, 2/1, 8/0 en 8/1

TechHelp24
External Moderator
Posts: 4,854
Registered: ‎02-23-2004

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

I've just created a DOC and upload BB calculator

TechHelp24
Occasional Contributor
Posts: 9
Registered: ‎10-08-2013

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

Yes it's a trunk of 4 ports like you say 2/0, 2/1, 8/0, 8/1

External Moderator
Posts: 4,854
Registered: ‎02-23-2004

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

Is very interesting, Welcome in Club !

I've exact the same situation by a customer and working into a solution, but don't have really one.

the only one is, I got answer from Brocade to try change/set another Fillword, current I've exact the same config LE and Fillword 3.

I believe - in my case - and this is my opinion, the problem is caused due different FC cable leght, and since the Trunk is formed 2+2 Port the trunk itself work like a DPS = Dynamic Path Selection / EBR = Exchange-Based Routing, and this cannot distributed the Buffer correctly.

But this is all my Theory, practices side is another story...... and I've to wait till the customer have a window to made some test

TechHelp24
Occasional Contributor
Posts: 9
Registered: ‎10-08-2013

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

Thanks for the reply Antonio , appreciate it !

I guess i have to wait for the other customer then.

I thought of busy lines during backup of the Continuous Access Replication of the EVA's but thats not the case because i check the rates every day now and see what happened on the SAN network last night.

This all come to light when we had error messages on the EVA storage "Exceeded data exchange rate"

And i'm situated in the center of Holland.

Cheers,

Henrico

Valued Contributor
Posts: 931
Registered: ‎12-30-2009

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

Hi Henrico

The "Excessive data exchange retry rate" indicates a issue in the replication path, this could be as a result of not following the CA implementation guide. I t contains parameters you should set depending on the replication protocol etc..

It could also be errors on the link so check your portcounters. Most likely you want to reset the counters first to give you a better insight on which counters are moving.

Have you called HP already to let them now you're having issues?

On a side note, Utrecht perhaps,Leusden apparently and working for Ten.

Say hi to Marije please.

I'm a dutchie as well (Leiden). Not that the location has anything to do with the error

Occasional Contributor
Posts: 9
Registered: ‎10-08-2013

Re: High Time BB_Credit Zero on ISL Downstream / trunkmaster

Hi there bongiorno

I downloaded your calculator but what do you mean by this line :

Type in the frame "Payload" size in Bytes (in cell D19)=======>

What you mean by payload ?

regards,

Henrico Lebbink

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