MD3600i - dual controller, 2 10Gbps iSCSI ports per controller, jumbo frames enabled on switch and array
2 MD1200's and 1 MD1220 both with dual EMM
3 RAID 10 virtual disks
2 RAID 6 virtual disks
out of warranty
VD's are mapped to hyper-v 6 node cluster and nothing has changed since this storage was implemented five years ago.
Ownership/preferred path has 3 VD's on controller 0 and 2 VD's on controller 1. Five months ago, we got the warning "virtual disk not on preferred path due to failover." The hyperv owner node was rebooted and the problem went away. The problem returned and rebooting the nodes didn't help so the recovery guru steps were followed. It appears that iscsi connections between the nodes (2 each), the two stacked switches, and the two MD3600i controllers are all linked solid with jumbo frames enabled throughout. There are two VLANS for the iSCSI networks. Cabling and switch ports have been changed.
Redistribute virtual disks and they go back to their preferred path on controller 1 but failover to controller 0 after exactly 10 minutes. At 5 minutes, there is an informational event "Virtual disk I/O shipping implicit transfer" then the failover at 10 minutes. If there is no activity on the VD's, they maintain their path on controller 1 indefinitely. Does this sound like the controller card needs to be replaced?
Are you using native MPIO drivers on your host or MPIO drivers that are from the resource cd? What is the current version of firmware that is on your MD3600i?
You want to make sure that you are using the MIPO drivers that is on the resource cd & not native to windows.
Please let us know if you have any other questions.
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Hi DELL-SAM L,
I have installed the host only features from the resource CD on all six hosts. This includes the MPIO driver and I see Dell MD Series Device Specific Module for Multi-Path version 1.3.1306.713.
Firmware is latest for every component:
Can I get you to gather a support bundle from your MD3600i so that we can review it? I will send you a private message that you can reply to with the support bundle.
Same issue, had the MD3600i working fine for 3 years.
HD failed in one of the VD. It got replaced, all good, but now the OTHER VD keeps popping with this message:
Virtual disk not on preferred path due to failover
I can change it manually, but it will do it again
No idea why that is happening suddenly (no other changes were ever made)