ZotacNano

Zotac Nano notes

After several years without issues (not counting integrated M.2 SSD that was gone after 2 years). using

• ZOTAC CI327 Nano passive cooled PC with 4GB RAM, 32GB SSD, and external 1TB USB disk (for VirtualBox images)
• pre-installed Windows 10 Home N, 64-bit

Things are now crumbling:

• sometimes on power-on there are long beeps (power-cycle helps)...
• occasional font corruption (characters disappearing) under openSUSE 15.5 LEAP, XFCE
• NOTE: memtest 86+ run whole pass without single error (my experience is that typical memory error occurs in first 30 minutes or never)
• occasional freeze of computer needing power cycle. At boot time found:

mcelog[755]: mcelog: Family 6 Model 92 CPU: only decoding architectural errors
mcelog[755]: mcelog: Family 6 Model 92 CPU: only decoding architectural errors
mcelog[755]: Hardware event. This is not a software error.
mcelog[755]: MCE 0
mcelog[755]: CPU 0 BANK 4
mcelog[755]: ADDR fef13580
mcelog[755]: TIME 1707243278 Tue Feb  6 19:14:38 2024
mcelog[755]: MCG status:
mcelog[755]: MCi status:
mcelog[755]: Uncorrected error
mcelog[755]: MCi_ADDR register valid
mcelog[755]: Processor context corrupt
mcelog[755]: MCA: Internal unclassified error: 408
mcelog[755]: Running trigger `unknown-error-trigger' (reporter: unknown)
mcelog[755]: STATUS a600000000020408 MCGSTATUS 0
mcelog[755]: MCGCAP c07 APICID 0 SOCKETID 0
mcelog[755]: MICROCODE 48
mcelog[755]: CPUID Vendor Intel Family 6 Model 92 Step 9

Some search results:

• useless support from Intel: https://community.intel.com/t5/Processors/Intel-Celeron-N3450-throws-an-error-while-booting-the-system/m-p/421105

Suspecting that it is caused by micro-code update, because:

 dmesg | grep '\(mce\|micro\)'

[    0.000000] microcode: microcode updated early to revision 0x48, date = 2021-11-16
[    3.025607] microcode: sig=0x506c9, pf=0x1, revision=0x48
[    3.025802] microcode: Microcode Update Driver: v2.2.
[    3.025818] mce: [Hardware Error]: Machine check events logged

Notice that MCE (Machine Check Exception) error occurs shortly after microcode is updated...

Trying to disable microcode by following Gentoo :-) manual:

• https://wiki.gentoo.org/wiki/Microcode#Dracut
• created file /etc/dracut.conf.d/98-disable-microcode.conf with content:

  early_microcode="no"
  

• and regenerated latest initramfs with:

  dracut -f --kver=`uname -r`

• did not help, but found https://wiki.debian.org/Microcode that passing dis_ucode_ldr should help. Appended to /etc/default/grub:

  GRUB_CMDLINE_LINUX_DEFAULT="mitigations=off rfkill.default_state=0 dis_ucode_ldr"

• and run:

  grub2-mkconfig -o /tmp/grub.cfg
  diff /tmp/grub.cfg /boot/grub2/grub.cfg 
  # review changes and then...
  cp /tmp/grub.cfg /boot/grub2/grub.cfg 

• this helped disable ucode, but MCE is still there...
• time will tell if it also helped other stuff

Also installed zypper in acpid to ensure that system (if not frozen) will attempt shutdown when Power button is pressed.

Font corruption

Found some similar issues:

• Available GTK/GDK debug options https://docs.gtk.org/gtk4/running.html
• GTK4 apps render badly on VirtualBox with 3D acceleration passthrough enabled: https://bugzilla.redhat.com/show_bug.cgi?id=2274930

Some examples:

$ GDK_BACKEND=help /usr/bin/gnome-terminal

Supported GDK backends: wayland x11 broadway

No output:
GSK_RENDERER=help /usr/bin/gnome-terminal
GSK_DEBUG=renderer /usr/bin/gnome-terminal
GSK_DEBUG=opengl /usr/bin/gnome-terminal
GSK_DEBUG=vulkan /usr/bin/gnome-terminal

After many years(!) I have found that there are actually 2 accelerated X11 i915 drivers for Intel:

• "intel" driver (/usr/lib64/xorg/modules/drivers/intel_drv.so, package xf86-video-intel)
• "modesetting" driver (/usr/lib64/xorg/modules/drivers/modesetting_drv.so, package xorg-x11-server)

You can switch between these two by using /etc/X11/xorg.conf.d/50-device.conf:

Section "Device"
  Identifier "Default Device"
  #Driver "intel"
  Driver "modesetting"
EndSection

Above is for modesetting driver. For intel just swap these 2 lines. For many years I always used intel, but found interesting discussion on Arch Linux wiki: https://wiki.archlinux.org/title/Intel_graphics

Some (Debian & Ubuntu, Fedora, KDE, Mozilla) recommend not installing the xf86-video-intel driver, and instead falling back on the modesetting driver. See [1], [2], Xorg#Installation, and modesetting(4). However, the modesetting driver can cause problems such as screen tearing and mouse jittering on XFCE, artifacts when switching virtual desktops in Chromium, and vsync jitter/video stutter in mpv.

So after many years I'm now testing modesetting to see it there will be same font corruption problem.

Please note that modesetting driver is totally unusable for VMware SVGA under VirtualBox...