I have Unraid 6.8.0-rc7 running on my HP Proliant DL380 G7 server. My server has the following setup:
Dual Intel Xeon E5649

72GB DDR3

LSI 9201-8i P20 HBA card

HP SAS expander

512GB NVMe SSD

NVIDIA Quadro P400

 

The BIOS is flashed to the 09/30/2010 version for quieter fans.

 

After a few days of running the system with the BIOS settings reset, I started receiving NMI processor lockups similar to the following message:
 

NMI: IOCK error (debug interrupt?) for reason 61 on CPU 0

Many of the search results for messages like the one above talk about updating the BIOS and setting different kernel flags to address HP's ILO 3 NMI watchdog. I know that HP provides drivers for RedHat for the ILO 3 NMI watchdog, but I haven't seen any for Slackware and I'm not sure how I would go about installing an rpm driver in a non RedHat distribution. I tried flashing the newest BIOS from 2018 and got the same results. I also added the following kernel flags to the Syslinux Configuration, but still got the NMI messages:
 

intremap=off panic_on_unrecovered_nmi=1 unknown_nmi_panic=1 nmi_watchdog=0

According to Slackware's documentation on the nmi_watchdog flag, you should set it to "1" first. If you run "cat /proc/interrupt | grep NMI" and it returns 0, then you should then try setting it to "2" to see if that makes a difference. I've tried both "1" and "2" and neither seem to make a difference. Setting the flag to "0" turns off the watchdog.

 

I was eventually successful though. With some fiddling with CPU settings in the BIOS, I managed to get these messages to disappear when turning off VT-x and VT-d. I suspect that the issue is related to VT-d and not VT-x, but I haven't yet tested with just VT-x enabled. I know that the CPUs are fine because prior to unRAID, I used to run Windows Server 2019 with VMs without issue.

 

Has anyone else seen these errors with VT-x/VT-d? Maybe this is a Linux kernel issue? It would be nice to be able to use both of these CPU features for VMs, but it's not too bad if it doesn't work since I mainly use Docker containers.

Edited December 5, 20196 yr by pcmantinker
I missed the SAS expander card in my spec list

I just wanted to post a follow up to my original post. I am now running unRAID 6.8.1 and have been successfully running VMs for the past couple of months with VT-d turned off. It seems to be the way HP configured hardware passthrough on this machine and how it interacts with the Linux kernel. This is a strange case, but none of my VMs need hardware passthrough so it's not a big deal.