8 Gb SAN switch ISL unstable at 8Gb, stable at 4 Gb

[Roald Eikas]

Scenario:

- Two sites - connected with single modus fibrecable - maybe 300m long

- Brocade 8Gb SAN switches for Hp Blade-c, two at each site (let's call them A and B at site1 and C and D at site2

- Long distance GBIC's

- ISL beetwen A and C and between B and D

- SAN-replication in synchronious mode

Problem:

- Running ISL at 8Gb is not usable - it is unstable and generates lots of errors

What to do:

- Extended fabrics mode - changing for L0 to LE - is that an option I should try, even though the cable length is shorter than 1 km?

- Does the TX Power/RX Power values on each side tell anything that is helpful? They vary from 250 to 580

[KurtG]

Singelmodus 9/125 micron fiber fiber? (all the way including patch fibers) - Do NOT mix and match different types of fibers on the same links. 

If so you should be ok up to 10km with a intersection loss of 2.19db (www.hp.com/go/sandesignguide)

Do you see escalating tx/rx errors on the switchport? (Do a delta check)

Is this the same on both ISLs?

Certified GBICS?

Power variations could be a sign of failing gbic but if it varies on both side of the link it might be something else. 

Some more info regarding swicthmodels, fos version, type of gbics, fiber cables etc might be of value. 

KurtG

[Roald Eikas]

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 Singelmodus 9/125 micron fiber fiber? 

- Yes

Do you see escalating tx/rx errors on the switchport? (Do a delta check)

- Yes

Is this the same on both ISLs?

- Yes

Certified GBICS?

- AJ717A OEM

Some more info regarding swicthmodels, fos version, type of gbics, fiber cables etc might be of value.

- Brocade 8/24c for HP Blade with FOS 7.0.2.a