MSA1000, red. Controller, internal Switch 2/8

[jroosen]

Hello,
I have some questions regarding a cluster-setup with single-hba and the above components.
The MSA1000 is equipped with a red. Controller and 2 SAN-Switches 2/8 (the internal ones).
Clusternodes are Netware-Servers each with 1 QL2300 HBA. Second HBA's for true multipathing should be installed later.
In the meantime the idea is to connect half of the servers to one of the SAN-switches, the other half to the second SAN-switch AND
to connect both switches with each other via an ISL, so half of the servers connect to the active MSA-Controller via the ISL.
After setup of the devices and connecting the switches with an ISL, I realized in the webmanagement of the SAN-switches that the port status of the ISL-Port is online but segmented. Port-Type tells me E-Port (segmented, domain-overlap).
Question: Why is this link blocked? Isn't it the meaning of an e-port to cascade switches to build a new switching-domain with more ports?
OK, nevertheless I changed the domain-id of the second switch (from default 1 to 2) and my isl-ports began forwarding. But when I connect my servers to the switches, only one-half of them (the ones attached to the switch connected to the primary controller) can connect to the array.
The other half of the servers can not connect.
Why does it behave like this?
What am I doing wrong?

[Uwe Zessin · Accepted solution]

Domain IDs need to be unique in a fabric, so this explains why you got segmentation.

But you still have an invalid configuration!

MSA1000 controllers are currently working in a strict Active/Standby configuration, which means that all logical disks are served by one controller at a time.

- cut the ISL between both switches
- connect all single-path servers to one switch only
- a single fibre channel adapter must not have access to both MSA1000 controllers
- a MSA1000 controller must not have access to more than one fibre channel adapter from a single host

(some of these rules are not explicitly spelled out in HP's documentation, but that's my conclusion from user reports here on ITRC)

[jroosen]

Yes, one controller is active primary and the other one standby.
But why can't I access the controller via the ISL. When I have the active controller in bay1/switch1 and a single server on the switch2, why is the drive not accessible. Doesn't make this domainrouting senseless?

[Uwe Zessin]

Sigh, I was pretty sure I have already responded to you, but it seems ITRC has dropped it :-(
I'll try again...

Is there any multipath software running on the NetWare servers? Did you check the SCSI target WWNs via the adapter's diagnostics? My guess is that the servers attached to the second switch have detected the second MSA controller port, first.

Connect to the second switch and disable the MSA controller's port or remove controller #2. Then try to connect all servers again.

[Glenn N Wuenstel]

Morning,
Just to add a few things to what Uwe has stated.
This is an unsupported configuration which means just that -- don't call HP looking for support of this config -- but that doesn't mean it won't work.
Thoughts:
1. Unplug the redundant controller until you get the second HBAs installed. Right now if it picked up you'd have problems unless you've got some multipathing software installed.
2. You should be able to ISL the two switches and see everything as if it were one big switch (it is one fabric and the 2/8 are just like other external switches).
3. Zoning would be useful here as everywhere. If you want to leave the redundant controller in place then just don't zone it into the configurations. I'd suggest a host-centric zoning where each HBA gets its own zone and then add the controller to that zone.

The easiest thing is to move all the servers to one switch and remove the second controller until you get your second HBAs installed. You aren't gaining anything by having the servers on two switches at this time since the second controller is in standby. Once Active-Active is released then you can choose to have a particular LUN active on a particular controller but not now.

Hope this helps,
Glenn