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Can't see LUNs via standby controller on MSA 1000

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Graham Whiteside
Occasional Visitor

Can't see LUNs via standby controller on MSA 1000

I'm an MSA newbie and I need some help with a problem I'm having with an MSA1000.

The MSA has two controllers, each with a single fibre port. The primary controller is connected to server A, and the standby controller is connected to server B. Servers are running NT4.

The idea is that if server A fails, the Admin turns it off, and powers up server B (a clone of server A).

The problem is that I can't see the LUNs via the standby controller. I have tried the following:

1) Unplugging the fibre from the primary controller.
2) Removing the primary controller.
3) Connecting server A to the standby controller, and server B to the primary. Again the server connected to the standby controller cannot see the LUNs.

One other thing to note - the LUNs were created using ACU with only the primary controller installed. The backup controller was added later. Not sure if this is significant.

I know the configuration must work because we have another MSA in the same configuration and it works fine!

Any help would be greatly appreciated.
9 REPLIES
Getmein4san
Occasional Visitor

Re: Can't see LUNs via standby controller on MSA 1000

Just the Standby controller has configured exactly the same the primary controller.
Stephen Kebbell
Honored Contributor

Re: Can't see LUNs via standby controller on MSA 1000

That last answer does not make much sense. Not sure if you can configure the controllers individually.

What firmware is on the MSA1000? What does ACU say about the 2nd controller? Do you use Selective Storage Presentation?

Regards,
Stephen
Graham Whiteside
Occasional Visitor

Re: Can't see LUNs via standby controller on MSA 1000


I'm not sure what the firmware level is - I'll need to check.

When I run up ACU on the server connected to the primary controller, the standby isn't mentioned. If I do the same on the server connected to the standby, it displays a message reporting that the controller is a standby and therefore can't be reconfigured.

In relation to Selective Storage Presentation, can I check this through ACU? I don't remember seeing an option for it.

Thanks,

Graham.
Stephen Kebbell
Honored Contributor

Re: Can't see LUNs via standby controller on MSA 1000

Hi,

it should be possible in ACU. I haven't got one in front of me, but there should be an option there. When you select the MSA, you should see an option for SSP in the top-rigth window.
Are the any error messages on the front panel of the MSA controllers?

Can you get the serial cable for the MSA controller, connect to it via HyperTerm and use the show commands to have a look at the controllers. In particular the commands show this_controller, show other_controller and show connections

Here's the CLI Reference Guide:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00683579/c00683579.pdf

Found this in the maintenace and service guide about comparing firmware version on the controllers when you hot-add a controller.
NOTE:
There is the possibility that a specific version of firmware may not be compatible with certain hardware revisions of a controller. In this scenario, the firmware on the two controllers is compared, and the version that is compatible with both controllers is copied to the controller with the incompatible firmware version. However, if the controller that is updated is already operating and processing I/O, it is not reset. The MSA does not enter redundant operation and an appropriate message is shown on the display. After the MSA has been shut down and powered back on, the controllers are then be able to enter redundant
operation. On a subsequent power cycle, both controllers enter redundant mode.

The guide is here, see page 105:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00800928/c00800928.pdf

Regards,
Stephen
Graham Whiteside
Occasional Visitor

Re: Can't see LUNs via standby controller on MSA 1000

Stephen,

The array has been power cycled since the backup controller was put in.

I'll have a look in ACU for SSP. I can see the disks from either server if connected to the primary controller, so I'm not convinced this is the reason.

Unfortunately I don't have a serial cable. Do you know what the part number is?

I'll be going to visit the customer next week, so I'll have a look then.

Thanks again for your help.

Regards,

Graham.
Graham Whiteside
Occasional Visitor

Re: Can't see LUNs via standby controller on MSA 1000


Sorry for the delay...

I have been to the customer and collected some info via the serial cable.

The standby controller seems to stay in standby mode even if the fibre is unplugged from the primary. (surely this would constitute a failure?)

If I remove the primary controller, the standby shows the mode as: "Not Redundant (ICL Not Established)"

I have attached show_techsupport from the primary controller.

Any help would be appreciated.

Regards,

Graham.
Stephen Kebbell
Honored Contributor
Solution

Re: Can't see LUNs via standby controller on MSA 1000

Hi,

usually it is multipathing software which triggers a failover. Unplugging the fibre cable would probably not cause a failover. The firmware is identical, it's active/passive. But the controllers have different Hardware revisions. The primary (this_controller) has Rev. A, the other one has Rev. 7. I don't know if that is significant.
I am not sure if this configuration is supported. For a cold-standby server, your best bet would be to remove the 2nd controller, get hold of a SAN switch or Hub, connect the 2 servers and the MSA controller to this and go from there. I honestly don't know exactly how you "force" a failover.

SSP does not appear to be active. (No ACL entries)

I don't know if installing MPIO, or upgrading to Active/Active firmware, or both, would help.
Sorry, but I'm out of ideas at the moment, maybe someone else could contirbute? Or you could try calling HP support.

Regards,
Stephen
Graham Whiteside
Occasional Visitor

Re: Can't see LUNs via standby controller on MSA 1000


The thing that confuses me is that this configuration works at a different site!

I think it may be a case of "spot the difference" between the config of this array and the original.

Interesting that you say Active-Active firmware is available - I thought these arrays were only available as Active-Standby. Do you know which firmware revisions are Active-Active?

Thanks again for your help.

Regards,

Graham.
Rob Leadbeater
Honored Contributor

Re: Can't see LUNs via standby controller on MSA 1000