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Occasional Contributor
Posts: 10
Registered: ‎05-15-2012

Swap 4Gb brocade switch for an 8Gb switch

Hi

I currently have a redundant fabric with a 4Gb switch cascaded to an 8Gb switch.  4Gb >> 8Gb via a single ISL    This configuration is FabricA and I have the same configuration as FabricB to give me multipathing.

I now would like to replace the 4Gb swtiches with an 8Gb switches to give me 8Gb >> 8Gb fabric for both fabricA and fabricB.

I need to rack the new 8Gb swtich in the same rack as the 4Gb switch which is in a different room to the cascaded 8Gb switch

My plan is the following and I would appreciate any feedback on the process please.....

ON FABRIC A

Failover all IO to Fabric B

Rack the new 8Gb switch below the existing 4Gb switch

Ensure the new switch is at the same firmware level as the existing fabric

Ensure the new 8Gb switch is clear of any zoning configs

Set a unique DID on the new 8Gb switch

connect an ISL between the new 8Gb switch and existing 4Gb switch

Allow the zoning configuration to propogate

Relocate cables from the 4Gb switch to the new 8Gb switch

Test successful server connectivity on Fabric A

Failover all IO to Fabric A

repeat the above steps for Fabric B

QUESTION:

As I am using WWNN zoning only can I now simply move the fibre cables from the 4Gb to the new 8Gb switch and the zoning will take care of the changes?

Would I be better off turning off the old 4Gb switch setting the DID of the new 8Gb to that of the 4Gb switch?
.

QUESTION:

If the answer to the above is YES.... can I also do this with the ISL link so the existing 8Gb switch is now cascaded from the new 8Gb switch?

QUESTION:

Once all the cables have been moved from the old 4Gb switch to the new 8Gb switch do I need to do anything to remove any references to the old 4Gb switch from the fabric?

many thanks

CL

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

Re: Swap 4Gb brocade switch for an 8Gb switch

QUESTION:

As I am using WWNN zoning only can I now simply move the fibre cables from the 4Gb to the new 8Gb switch and the zoning will take care of the changes?

Would I be better off turning off the old 4Gb switch setting the DID of the new 8Gb to that of the 4Gb switch?

Well this depends, from the zoning point of view it really don't matter because you use wwn based zoning.

But some OSsen like HPUX are sensitive to changing port id's, which is related to the DID.

So the question would be do you what kind of OSses are involved here?

QUESTION:

If the answer to the above is YES.... can I also do this with the ISL link so the existing 8Gb switch is now cascaded from the new 8Gb switch?

I would do the following in between step

  • Allow the zoning configuration to propogate

and step

  • Relocate cables from the 4Gb switch to the new 8Gb switch

1 Switch ISL between 4G and 8G switch to 8G and 8G switch

2 Confirm fabric merges again.

So you start with new8G >> ISL >> 4G >> ISL >> old8G and end up with

4G >> ISL >> new8G >> ISL >> old8G.

After that move on with "Relocate cables from the 4Gb switch to the new 8Gb switch"


QUESTION:

Once all the cables have been moved from the old 4Gb switch to the new 8Gb switch do I need to do anything to remove any references to the old 4Gb switch from the fabric?


no just disable/remove the ISL and your done

Occasional Contributor
Posts: 10
Registered: ‎05-15-2012

Re: Swap 4Gb brocade switch for an 8Gb switch

Many Thanks

interestingly quite a few of the servers are running HP-UX and other flavours of Unix so does that mean that changing the Domain ID to match the 4Gb switch is the preferred method - and I guess I should then ensure that the cables are also relocated to the equivalent (same) port number on the new switch?


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

Re: Swap 4Gb brocade switch for an 8Gb switch

Making sure that the port ID's are the same, makes it more easy on the HPUX hosts.

If PIDs change it still doable but you may expect more effort needed for your HPUX hosts

Occasional Contributor
Posts: 10
Registered: ‎05-15-2012

Re: Swap 4Gb brocade switch for an 8Gb switch

That's great - many thanks

So just to clarify - As HP-UX is involved, I need to maintain the DID on the new swtich...? So I initially set a unique DID on the new switch to allow the zoning to propogate then once this is complete move the fibre cables into the same port number on the new switch and then to change the DID of the new switch to match that of the 4Gb switch to avoid any potential OS issues?

One final question:

I've tested this in a lab and all is fine, the only thing I saw that I wasn't really expecting was that with the 4Gb switch I could expand the 'port' option under the 'zone admin' 'alias' section and could see the other two switches..... with both the 8Gb switches I could only see the local switch and not the others that were connected via the ISL's. Now this doesn't really matter as I'm using WWN zoning and not port zoning but would like a reassurance that this is expected behaviour - perhaps it's a firmware thing as the 4Gb (200e) switch is a running v6.0.2 and the 8Gb's (5100s) are running v6.4.2a

The Name Server was reporting back the devices across all switches and WWN zoning was functioning as expected so I'm hoping this is just removed functionality with the later versions of firmware

many thanks

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

Re: Swap 4Gb brocade switch for an 8Gb switch

Yep that's normal behavior and your guess is right, it has been removed from FOS,

However you can still zone using webtools and cli to add remotre wwn's.

If you want that functionality back, please consider using BNA.

Occasional Contributor
Posts: 10
Registered: ‎05-15-2012

Re: Swap 4Gb brocade switch for an 8Gb switch

cool

When I add the ISL from the new switch to allow the zoning to initially propogate to the new switch will this affect IO to servers attached to the existing switches on that fabric which the fabric is rebuilding?

e.g. should this be done with all the paths failed over to the redundant path?

many thanks

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

Re: Swap 4Gb brocade switch for an 8Gb switch

To be sure you can failover to the other fabric, but it should not be necessary as your multipath solutions (dm-multipath, secure-path.auto-path etc) should pick up lost connections that may occur during a rebuild.

At least that's what I observes with path failures, but to be honest I haven't seen it happen yet on fabric rebuild.

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