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EVA 8000 Managing Controller

 
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Mark Poeschl_2
Honored Contributor

EVA 8000 Managing Controller

We have an EVA 8000 with a large number of vdisks presented to some UNIX hosts. All have "preferred path" set to controller A or B Failover/Failback with about half the vdisks preferring controller A and half on B. Strangely, a significant majority of the vdisks report "Managing Controller" as controller B. Why are some of the disks that prefer controller A managed by controller B? Is there some kind of intelligent load balancing going on between the controllers? EVAPerf shows that controller A's CPU is much more likely to be the busier one during our peak times.
12 REPLIES 12
Rob Leadbeater
Honored Contributor

Re: EVA 8000 Managing Controller

Hi Mark,

Can you be more specific on the versions of UNIX that you're running ?

Cheers,

Rob
Mark Poeschl_2
Honored Contributor

Re: EVA 8000 Managing Controller

Tru64 5.1B-5
IBaltay
Honored Contributor

Re: EVA 8000 Managing Controller

Hi,
the issue could be the following:
a) after the swaping the managing controller role to the proxy controller and failback to the original managing controller, the host continues to write/read to the proxy controller and after a certain period of time it forces the role of the managing controller back to the proxy. Thats why the controllers need not be well balanced. Check the multipathing solution for the possible reasons to this behaviour... What UNIX are you using?
If HP-UX, then what version and what version of the multipathing?
the pain is one part of the reality
IBaltay
Honored Contributor

Re: EVA 8000 Managing Controller

Hi,
this could give some info...
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01552954/c01552954.pdf
the pain is one part of the reality
IBaltay
Honored Contributor

Re: EVA 8000 Managing Controller

Hi,
or maybe here for more docs:
http://h30097.www3.hp.com/docs/pub_page/V51B_DOCS/v51b_doclist.htm
the pain is one part of the reality
Uwe Zessin
Honored Contributor

Re: EVA 8000 Managing Controller

That version should properly detect optimized/non-optimized paths, but maybe the handling was disabled:

http://h30097.www3.hp.com/unix/erp/c01627023.html
.
IBaltay
Honored Contributor
Solution

Re: EVA 8000 Managing Controller

Hi,

New cam Attribute Controls Path Usage
http://h30097.www3.hp.com/docs/patch/51B/bl27/HTML/ch01s29.html?jumpid=reg_R1002_USEN

the pain is one part of the reality
Mark Poeschl_2
Honored Contributor

Re: EVA 8000 Managing Controller

Our cam_ccfg_aa_enable parameter is set to the default value of 1 which, as I understand from previous posts and the 'man' page should mean we're only using preferred paths. That doesn't sem to be the case.

Everybody's consensus seems to be that this is an issue with the UNIX servers rather than the EVA itself. Do I have that right?
Uwe Zessin
Honored Contributor

Re: EVA 8000 Managing Controller

Mark, you have checked that the operating system type on the Host object is set correctly for Tru64?
.