topic Re: EVA8100 Controlloer Failover in Disk Enclosures

EVA8100 Controlloer Failover

Abdul Rashid — Thu, 27 Nov 2008 16:24:44 GMT

We have an EVA8100 with quite a few LUNs configured and manually load balanced across both Controllers that is set to failover only option. The LUNs are presented to Windows hosts.

Controller B was rebooted and the all the LUNs failed over to Controller A and have remained on Controller A for a long time now. How can I get the LUNs configured to be on controller B back to controller B.

Thanks

Re: EVA8100 Controlloer Failover

Víctor Cespón — Thu, 27 Nov 2008 16:56:06 GMT

"Failover only" means that, if one controller fails, the vdisks switch to the other and stay there unless:

- More than 60% of the reads are coming from the non-owner controller
- You use MPIO DSM manager on the server to perform a manual failover
- You change the preferred controller in Command View
- The owner controller fails or it's rebooted

Re: EVA8100 Controlloer Failover

RM782 — Thu, 27 Nov 2008 17:00:39 GMT

Hi

You will need to use DSM Manager which integrates into the Microsoft Management Console this needs to be insatalled on each of your host that have multi-pathing software installed.

From within computer mangement there is a section under storge titled Hp MPIO DSM Manager highlight that section and then to the right there will be a list of luns assigned to that system, select the lun right click and a drop down list will be displayed giving various options on lun placement.

Or you could use HPDSM cli

Start - Programs - Hewlett-Packard - Eva -HPDSN Cli

Re: EVA8100 Controlloer Failover

IBaltay — Thu, 27 Nov 2008 17:09:04 GMT

Hi,
so all the paths are mastered by the controller A after the controller B reboot. At the same time the Set preferred path to the controller B reminded on some vdisks, but now the controller B is only the proxy controller. So you should wait for the hardcoded feature of the EVA controller, which automaticaly turns the heavily loaded proxy to the master controller...

Re: EVA8100 Controlloer Failover

Abdul Rashid — Thu, 27 Nov 2008 17:17:41 GMT

Thanks all for your prompt responses. As per IBaltay's response, does this mean that all the LUNs will automatically failback to its original controller if there is a heavy load on the EVA.

Thanks

Re: EVA8100 Controlloer Failover

IBaltay — Thu, 27 Nov 2008 18:45:29 GMT

one thing must be clarified here:
if you are using the host MPIO DSM ALB option and dynamic loadbalancing. Then the master controller is being chosen by the host multipathing software... then the set preferred path on EVA controllers should be set to NONE. (this should be the best config option and you dont need to bother with the static master controller mapping...
You can reconfigure your environment to this, but always check the performance after each change

But you probably dont use the ALB at the moment and you rely on the static loadbalancing setting on the EVA via the set preferred path evenly to both controllers to become masters....
Then my above statement is valid and you can check the paths correctnes via the hpdsm cli...

But as you have

Re: EVA8100 Controlloer Failover

Abdul Rashid — Thu, 04 Dec 2008 11:01:42 GMT

I have now installed MPIO Manager on my hosts, so how do I know from MPIO manager which Controller is currently owning the LUN and how do I failback to its original preferred owner without disrupting the IO.

Thanks