How does the dual controller on HPE MSA 2050 works? And where Can I find the settings for it?

[JasonKannte]

Dear All,

I am having a HPE MSA 2050 storage with two volumes, and one for each controller.  We had an incident in the server room, and one controller lost power for about 15 seconds.  And after the incident we find a lot of database server has inconsistant status on the log files, and some virtual server files corrupted.

I am wondering is this type of Storage has the function of failover on the dual controller?  Or if there is any configuration wrong for the storage?   -  I don't find any place to setup the failover for this.

Please help me on the question I have or give me some hints what happened to the failover.

[SUBHAJIT KHANBARMAN_1]

As you are dealing with MSA2050 which means your are dealing with Pool and Virtual Disk Group. From Pool you have created Volumes.

Please note that Controller only takes care of Pool and Virtual Disk Group (VDG) availability.

Volume availability depends upon how you have presented the volume to host. To be specific if volume presented to host with all Host ports or some host ports of both controllers or not. If not then volume will not failover successfully and you will face outage. Technically multi-path need to be configured from Host to both controllers of MSA

Hope this helps!
Regards
Subhajit

I am an HPE employee

If you feel this was helpful please click the KUDOS! thumb below!

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[SahanaR]

@JasonKannte 

Hi Jason,

There is no function or configuration change to be made in MSA to work as dual controller.MSA is designed to work in dual controller mode when there are 2 controllers installed.

For the array to failover to the partner controller you need to have redundant paths(managed through multipath software)

In the case of a direct attach configuration, the best practice is to have at least two connections to the array for each server. In the case of a direct
attach configuration with dual controllers, the best practice is to have at least one connection to each controller.

Please check the links below for better understanding,

Best pactice   https://h20195.www2.hpe.com/v2/getpdf.aspx/A00015961ENW.pdf?  (page 27)

cabling https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-a00028199en_us&docLocale=en_US

MSA 2050(gen 5) virtualization technology

https://h20195.www2.hpe.com/v2/Getdocument.aspx?docname=a00087404enw

Please let me know if this helps!

Thanks

[JasonKannte]

Hi SahanaR,

My environment is listed below:

4 hosts

2 fiber channel switch

1 MSA 2050

FC connection

Currently on the MSA 2050, we are connecting FC port 1 to the switch 1 , and FC port3 to the switch 2,  the same connection for both controller.

According to the Best practices, we need to connect FC port 1 and FC port 3 on switch 1, and FC port 2 and FC port 4 on switch 2, to get the redundency,

I want to understand the different ways of connection for the 4 Ports on the controller, can anyone help me on this?

[SUBHAJIT KHANBARMAN_1]

The setup which you have currently is not perfect because this is not fully redundant setup.

Currently on the MSA 2050, we are connecting FC port 1 to the switch 1 , and FC port3 to the switch 2,  the same connection for both controller.

According to the Best practices, we need to connect FC port 1 and FC port 3 on switch 1, and FC port 2 and FC port 4 on switch 2, to get the redundency,

We would recommend you to follow the best practice guide as this is giving you fully redundant setup. On top of that to remind you, you need to present volume with all host ports and configure multi-path at the host end with the help of multi-path software.

Hope this helps!
Regards
Subhajit

I am an HPE employee

If you feel this was helpful please click the KUDOS! thumb below!

*****************************************************************************

[SahanaR]

Hi Jason,

Thanks for sharing the configuration information.

Unfortunately I dont have an exact diagram for a failover configuration for your environment.But i might have something similar.

Please refer to page 6 on https://h20195.www2.hpe.com/V2/getpdf.aspx/4AA4-7060ENW.pdf?

Also i have attached a picture.

Thanks

[SUBHAJIT KHANBARMAN_1]

@JasonKannte 

Can you please help us to understand if the issue got resolved or not?

If issue got resolved then how?

Also request you to mark the forum as resolved if there is no more outstanding query from your end on this issue.

This will help for everyone who are all following your forum.

Hope this helps!
Regards
Subhajit

I am an HPE employee

If you feel this was helpful please click the KUDOS! thumb below!

*****************************************************************************

[SahanaR]

@JasonKannte 

Hi Jason,

Please let me know if my previous post was helpful or if you need any further assistance.

Thanks