Powervault constantly going into failover around the same time

Question

Hi All, I have a little problem with our powervault. A few weeks ago, we replaced the controller of one of our powervaults. It synced up perfectly with the configuration of the working controller and no issues were found after that. Unfortunately, 1/2 weeks ago, the problem began to start. around the same time every day (Say, 15:30/16:00/17:00) we get messages/mail that the Powervault started a failover to the other controller and after around 10 minutes jumps right back to the original controller/preferred path. if this happens, vmware machines are not reachable The machines attached are Dell Poweredges R710 with VMware (via a Dell Powerconnect switch). I already read something about redistributing disks but that's something you need to do with a maintenance window or as few I/O as possible if I'm correct? Does anyone know what to do? or does someone had this problem earlier? can this be related to the network infrastructure? Thanks in advance for your attention and reading this discussion/question Kind regards, Bjorn

DELL-Charles R · Accepted Answer

Hello Bjorn,

Thank you for the update.

The alert on the system is due to a virtual disk not being on the preferred path. When virtual disks are created, they are assigned to one of the two controllers as a preferred communication path. If that path is not available – due to a network issue, controller reset, etc. – the array will communicate via the alternate controller. In some cases the communication does not shift back to the primary path when it becomes available again. To correct this you just need to manually redistribute the virtual disks back to their preferred paths. You should not have to have a maintenance window for this.

To redistribute virtual disks:

1. Open Modular Disk Storage Manager (MDSM)

2. Click on the Support tab

3. Select Manage Raid Controller Modules

4. Click on Redistribute Virtual Disks

• You will get an alert telling you that this will disrupt communications if you do not have the multipath drivers installed. You can ignore this message and proceed. If you still have access to the virtual disk that is not on preferred path, you have multipath drivers installed

Check that the host mapped to both controllers. In the Admin guide page 55 explains about configuring host access.

https://downloads.dell.com/manuals/common/md32xx_md36xx_administrator%20guide_en%20us.pdf

Additional information in Dell PowerVault MD Series Storage Arrays: IP SAN Best Practices guide. Here is a link to the guide. https://www.dell.com/downloads/global/products/pvaul/en/powervault-md36x0i-ip-san-best-practices.pdf

Please let me know how it goes.

DELL-Charles R · Answer

Hello btenhoeve,

I'm sorry to see the controller constantly attempts a failover around the same time every day.

Is there a particular process that runs around that time?

What is the PowerVault model?

First recommendation would be make sure your firmware and drivers are current.

Please let me know.

btenhoeve · Answer

Is there a particular process that runs around that time?

- There is no process running around this time. (Not that I know, and didn't see a process running around this time)

What is the PowerVault model?

-MD3220i

First recommendation would be make sure your firmware and drivers are current.

-Something to keep in mind, indeed.

The weird thing is, that it didn't happen now for 2 days.
1 volume is now not on his preferred path. maybe the controller can only take that many connections in 1 controller?

Regards,

Bjorn

btenhoeve · Answer

Hi,

Thank you for the answer

The problem is not occurring since last week. one volume is still not on his preferred path but not wanting to touch that now (if it works, it works, right?).

Anyhow, if the problem will occur again, I will try this as possible solution.

Again, Thank you for the help.

Regards,

Bjorn

PowerVault

Powervault constantly going into failover around the same time

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