Skip to main content
Start a Conversation

Unsolved

This post is more than 5 years old

RaJos

8 Posts

909

May 4th, 2007 06:00

connetrix (fiber switch) in HA configuration with same domain ID

We have 2 64-ported fiber switch (connectrix).
These are configured as fcd domain id 97 (0x61).

Our hosts have 2 HBAs. Each HBA is connected to one port on each switch. So, each HBA goes to a separate switch.

These switches connect to symmetrix (dmx2000) on the backend.

powerpath is used on the hosts.

When I do ioscan -fC disk on the hp servers, for both HBA cards, I get this path
1/0/2/1/0/4/0.97.60.19.3.4.5
1/0/4/1/0/4/0.97.60.19.5.4.5

Usually, we see, second fiber switch configured as id=98 (0x62). So, the hp h/w path shows 98 in place of 97, avoiding confusion.

Now, the server is doing good. We have data going thru both HBAs (load balanced by powerpath).

My question is, whether this kind of switch configuraton is right, as you know, the switch are gives IDs 97 and 98? What kind of impact this has? If one of the switch goes down, then 97 is down, does it mean, all IO is stopped?

Thank you all.

Ra Jos

RaJos

8 Posts

May 4th, 2007 06:00

Usually I have seen domain id that each HBA goes to is, unique.
In this case, h/w config is correct. By isn't the switch config needs to be
made 97 for one domain and 98 for other.

What if 97 goes down, then powerpath thinks that it is down and stop all IO,
though physically each HBA is connected to a separate switch.

Ra Jos

dynamox

2 Intern

 • 

20.4K Posts

May 4th, 2007 06:00

you need to have unique domain id only if you are going ISL both switches together, in your case you have two separate fabrics so having the same domain id is not an issue. Powerpath is intelligent enough to look at the whole path to the disk, do determine which direction to send IO to in case one path fails. Your HBA's have different controller id ...so powerpath will figure it out and send it to the right one. If you were to have a switch/hba fail ..you will see that particular path being marked as dead in powerpath.

dynamox

2 Intern

 • 

20.4K Posts

May 4th, 2007 06:00

that number, in your case 97 will always show up in the path on HPUX. So if the domain id is set to 97 on both switches then it looks correct from the host perspective. Powerpath will re-direct IO to the available path, in case one of your switches fails.

Kiran3

410 Posts

May 8th, 2007 00:00

will you be able to test the failover by physically disconnecting one cable at a time?
this may not be possible depending upon your environment but it can clear your doubts :-)

View More

View All

No Events found!

Top