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Re: EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

 
Alzhy
Honored Contributor

EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

Just noticed all of my EVA LUNS have Path Preferencing set to NONE. From the server, it appears they're all active on one HSV 110 controller - which means during activity, that HSV110 is what's loaded (correct?).

Can I perform path preferencing online? I'd like to divvy up the VDISKS between the 2 controllers ..

And syntax in SSSU?
Hakuna Matata.
4 REPLIES 4
Ivan Ferreira
Honored Contributor

Re: EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

Yes you can do it online. Ensure to use evaperf to check the balanced utilization. Also, ensure that the preferred path from the host perspective to the EVA controllers are match the "preferred path" of the EVA controllers.

See the attached file:

Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
Uwe Zessin
Honored Contributor

Re: EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

The attached PDF is for an Active/Active EVA while VCS 3.028 is Active/Passive.

If I remember correctly, change the path referrence on the EVA might not produce the desired effect if there is active cache data on the current controller.

This is for HP-UX, right? In that case, "Path-[AB] - Failover/Failback" settings are not supported.

The supported way to cause static load distribution of vdisks across controllers is by setting the path preferrence with SPMGR. If necessary, it will tell the EVA to do a controller failover for a virtual disk.

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Alzhy
Honored Contributor

Re: EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

Uwe,

You mean leave the PATH Preferencing on CV at "None" but do "spmgr select" on the host / SecurePath end - alternating between controllers?


Hakuna Matata.
Uwe Zessin
Honored Contributor

Re: EVA5K VCS 3.028 (Active/Passive) - Can I perform Path Preferencing Online

Sorry if I did not make it clear:

- use "Path A/B - failover only" to distribute at the next boot of the EVA

- use SPMGR to force any changes now
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