From time to time you may encounter an error where your VxRail node goes into a device missing state in VxRail manager but is operating normally in vCenter. The main culprit behind this is typically the PTAgent. The PTAgent exists to poll hardware information on a node every few minutes using ipmi. Assuming there isn’t a bug with the version of PTAgent running on your VxRail then the below is a good starting point troubleshoot.
Step 1. See the version of PTAgent you have. Good to cross check against recent release notes to see if there is a known issue fixed in an upgrade.

#esxcli software vib list | grep dellptagent
Step 2. Check the ISM service, stop, start, check.

#/etc/init.d/dcism-netmon-watchdog status
#/etc/init.d/dcism-netmon-watchdog stop
#/etc/init.d/dcism-netmon-watchdog start
#/etc/init.d/dcism-netmon-watchdog status
Step 3. PTAgent service stop, start, status

#/etc/init.d/DellPTAgent status
#/etc/init.d/DellPTAgent stop
#/etc/init.d/DellPTAgent start
#/etc/init.d/DellPTAgent status
Step 4. Check if VxRail is listening

#esxcli network ip connection list | grep LISTEN | grep Dell
–grab 4869528
#ps -s | grep 4869528
Step 5. Should all of the above fail — Reboot
Put the node in maintenance mode and reboot it.
After it comes back restart the VxRail manager VM.
Wait 5 to 10 minutes and check for the node status.
Step 6. If all of the above fails – Call DellEMC support.
Summary:
From time to time you will have to troubleshoot the VxRail. These are a handful of good troubleshooting tricks and tips you can execute while waiting for support to call you back. I hope you found this article useful.