Windows Server 2019 Hyper-V guest VM ISCSI MPIO disconnects

Hi,

I thought I would update on this as I have finally managed to get it working. The changes I made were :-

Production (x3 nic team) - only available to VM's
Fault Domain vSwitches (1 nic x2 FD's) - only available to VM's

The HyperV host has its own migration/management NICs and Fault Domain connections. All in all I have 11 cables plugged across x3 network cards. Could probably drop x2 connections as the HyperV host FD NIC-Teams dont really need a standby adapter.

On both the HyperV host and VMs I ran PS:

disable-netadaptervmq *
disable-netadapterrsc *
disable-netadapterrss *
disable-netadapterlso *
disable-netadapterchecksumoffload -name * -udpipv4
disable-netadapterchecksumoffload -name * -udpipv6
disable-netadapterchecksumoffload -name * -ipipv4

new-msdsmsupportedhw -vendorid "COMPELNT" -productid "Compellent vol"
new-msdsmsupportedhw -vendorid "Dell EMC" -productid "ME5 "

I think, if I was to put my finger on something that resolved the issue, it was disable-netadapterlso * within the HyperV guest. This seemed to really kick it in to life. I can now connect the guest OS' directly to the SAN without having to create a CSV, VHD and then copy the files in to the virtual hard disk.

Gary

Hello Gary,

Thank you for your question and for reaching out with your question today.

Based on the information provided, it seems you are experiencing intermittent connection issues with the iSCSI volume within the Hyper-V guest. Here are a few troubleshooting steps you can try to resolve the problem:

1. Check network connectivity: Ensure that the network connections between the Hyper-V host, virtual switches, and the iSCSI device are stable and without any packet loss. Verify the network configurations, such as IP addresses, subnet masks, and default gateways, to ensure they are correctly set up.
2. Update NIC drivers and firmware: Ensure that you have the latest drivers and firmware installed for the network interface cards (NICs) on both the Hyper-V host and the guest OS. Outdated drivers or firmware can sometimes cause connectivity issues.
3. Verify MPIO configuration: Double-check the MPIO (Multipath I/O) configuration on both the Hyper-V host and the guest OS. Make sure you have properly configured MPIO with the correct paths and load balancing settings. You may also want to review any MPIO-specific settings provided by your iSCSI device manufacturer.
4. Adjust iSCSI timeout settings: The default timeout settings for iSCSI sessions might be too short for your environment. Try increasing the timeout values on the Hyper-V host and the guest OS to allow for longer connection retries. You can modify the timeout settings through the iSCSI Initiator properties.
5. Monitor network traffic: Use network monitoring tools to observe network traffic between the Hyper-V host and the iSCSI device. Look for any patterns or anomalies that may indicate network issues, such as high latency, dropped packets, or congestion.
6. Test with a different iSCSI device: If possible, try connecting to a different iSCSI device or target to see if the issue persists. This can help determine if the problem is specific to the current iSCSI devices or if it's a more general configuration issue.
7. Consider contacting the iSCSI device support: If the issue persists after trying the above steps, it may be beneficial to reach out to the support team of your iSCSI device manufacturer. They can provide further guidance and assistance in troubleshooting the specific device and configuration.

Remember to backup any important data before making any changes to your configuration or attempting further troubleshooting steps.

I used AI provided by ChatGPT to formulate part of this response. I have verified that the information is accurate before sharing it with you.

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Best regards.

Hey,

I think your issue might be related to your network configuration. Have you configured MTU (Jumbo Frames) on your adapters/team? It might cause issues. In addition, I prefer using iSCSI over separate NICs (not in a team) and use MPIO instead of teaming. You can try removing your team and test connection via single interface and see how it works. As another option, you can try using StarWind VSAN to test if other iSCSI targets work in your configuration.
https://www.starwindsoftware.com/starwind-virtual-san

Cheers,  
Alex Bykovskyi  
StarWind Software  
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