replace switch: what will change

Question

I have a HP UNIX cluster(two node) connect to a EMC DMX800 with dual fabric, each fabric is a brocade 2800 switch( a very old switch with SC port). now i want to replace the switch with brocade 5000 series switch. what will change in this replacement? any suggestion?
i heard of that since the core PID of these two generation switch is different(0, 1), so the device number(c#t#d#s#) in HP host will change, but i don't know if the LV or VG will be affected.
and should the config in DMX800 be modified? also since the device number changed, the quorum disk of HP cluster should be modified, is this true?

xe2sdc · Accepted Answer

Dingding I guess your message can receive more interesting answers in the Connectivity area of our forums .. that's where we usually talk about switches and SAN devices ...

However before moving the thread, let me try to answer your question...

1) core pid is the last of your problems .. HPUX binds virtual controllers to switch port FCID. Moving from old to new switches probably will change the domain identifier and possibly also switch port where the storage is connected.

2) changing any of _storage port number_ or _switch DID_ will impact the "hardware path" used by HPUX to identify your disks. This will change the c#t#d# (I guess hpux isn't using slices since hpux 9) and will definitly impact LVM.

3) LVM stores its configuration in a file (/etc/lvmtab) that you can't change via usual editors. lvmtab contains name of all disks belonging to all VGs. You have to update lvmtab before c#t#d# changes (removing soon-to-be-removed paths) via vgreduce command, migrate paths from old to new switches, discover new c#t#d# and add new paths to VGs (vgextend) to reflect thanges in lvmtab.

4) yep the quorum disk will be affected. Plan an offline of the whole cluster to reconfigure it when moving Cluster Locks to new paths. However probably someone may give better/different advices here

xe2sdc · Answer

Ok Dynamox .. are you ready ?? So let's shout (just like it happens in Extreme Makeover Home Edition) .. MOVE THAT BUS !!! Whoops move that thread .. Message was edited by: Stefano Del Corno

dynamox · Answer

to add to Stefano's reply, Brocade 2800 is a 1G switch so before you move it to the new switch, ask your CE to check in the bin file to make sure all FA ports are set to auto negotiate so when you swing the cable to the 5000 switch it will login at 2G. I've had an instance where symcli was showing that FA was set to auto negotiate but it would not login at 2G no matter what i tried via symcli. Had to get CE to change it to auto in the bin file.

xe2sdc · Answer

Regarding DMX800 .. as long as fabric protocol (FC-AL/FC-SW) won't change, there is no need to change DMX800 config AFAIK.

dingding1 · Answer

many thanks! very very useful! as you say, HP use the switch port FCID, so even if i keep the same port connected and the Domain ID the same(so your answer 2 is not taken into account), the change of core PID will still affect the area id, which is part of the FCID. so the device path will definitely changed but not "probably".
after this task completed, i will be back to post the replace procedure.

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replace switch: what will change

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