Some info about my Pi
- DietPi
9.20 - Distro version
Debian Trixie - Kernel version
Linux A3ProdEngTV 6.12.47+rpt-rpi-2712 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1 (2025-09-16) aarch64 GNU/Linux - Architecture
arm64 - SBC model
RPi5 - Power supply used
stock RPi - SD card used
Samsung EVO
I recently tried running updates on one of my RPi 5’s and I was told that there was 0 available on /dev/root. I deleted a dietpi back up to free up enough space to run dietpi-update. Anyway, this is what I found:
~$ df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/root ext4 29G 27G 828M 98% /
devtmpfs devtmpfs 2.0G 0 2.0G 0% /dev
tmpfs tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs tmpfs 810M 52M 758M 7% /run
tmpfs tmpfs 5.0M 48K 5.0M 1% /run/lock
tmpfs tmpfs 1.0M 0 1.0M 0% /run/credentials/systemd-journald.service
tmpfs tmpfs 50M 352K 50M 1% /var/log
tmpfs tmpfs 2.0G 11M 2.0G 1% /tmp
/dev/mmcblk0p1 vfat 127M 34M 94M 27% /boot/firmware
tmpfs tmpfs 1.0M 0 1.0M 0% /run/credentials/getty@tty1.service
tmpfs tmpfs 405M 80K 405M 1% /run/user/0
tmpfs tmpfs 405M 48K 405M 1% /run/user/1000
~$
~$
~$ sudo du -h --max-depth=1 / | sort -h
du: cannot access '/proc/170175/task/170175/fd/3': No such file or directory
du: cannot access '/proc/170175/task/170175/fdinfo/3': No such file or directory
du: cannot access '/proc/170175/fd/4': No such file or directory
du: cannot access '/proc/170175/fdinfo/4': No such file or directory
0 /dev
0 /proc
0 /sys
4.0K /media
4.0K /opt
4.0K /srv
16K /lost+found
32K /tmp
44K /mnt
4.1M /etc
41M /var
45M /boot
52M /run
446M /home
1.7G /usr
24G /root
27G /
~$
~$
~$ sudo du -xhd1 /root | sort -h
4.0K /root/Desktop
8.0K /root/.ssh
20K /root/.local
76K /root/.pki
200M /root/.config
340M /root/.cache
24G /root
24G /root/logfile_storage
~$
~$
~$ ls -lh
total 24G
drwxr-xr-x 2 root root 4.0K Dec 10 11:17 apt
-rw-r--r-- 1 root root 8.0K Dec 10 11:17 dpkg.log
-rw-r--r-- 1 root root 1.7M Dec 22 12:17 lastlog
-rw-r--r-- 1 root root 13K Dec 22 12:17 wtmp
-rw-r--r-- 1 root root 24G Dec 22 13:17 Xorg.0.log # hello there...
After inspecting the Xorg log, I found the following lines being repeated over and over again:
[ 20.012] (II) modeset(0): EDID vendor "XXX", prod id 0
[ 20.012] (II) modeset(0): Using EDID range info for horizontal sync
[ 20.012] (II) modeset(0): Using EDID range info for vertical refresh
[ 20.012] (II) modeset(0): Printing DDC gathered Modelines:
[ 20.012] (II) modeset(0): Modeline "1920x1080"x0.0 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (67.5 kHz eP)
[ 20.012] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 1720 1760 1980 720 725 730 750 +hsync +vsync (37.5 kHz e)
[ 20.012] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync (45.0 kHz e)
[ 20.012] (II) modeset(0): Modeline "720x480"x0.0 27.00 720 736 798 858 480 489 495 525 -hsync -vsync (31.5 kHz e)
[ 20.012] (II) modeset(0): Modeline "1920x1080"x0.0 148.50 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync (56.2 kHz e)
[ 20.012] (II) modeset(0): Modeline "1920x1080i"x0.0 74.25 1920 2448 2492 2640 1080 1084 1094 1125 interlace +hsync +vsync (28.1 kHz e)
[ 20.012] (II) modeset(0): Modeline "1920x1080i"x0.0 74.25 1920 2008 2052 2200 1080 1084 1094 1125 interlace +hsync +vsync (33.8 kHz e)
[ 20.012] (II) modeset(0): Modeline "1920x1080"x0.0 74.25 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync (27.0 kHz e)
[ 20.012] (II) modeset(0): Modeline "1920x1080"x0.0 74.25 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (33.8 kHz e)
[ 20.012] (II) modeset(0): Modeline "1280x720"x0.0 59.40 1280 3040 3080 3300 720 725 730 750 +hsync +vsync (18.0 kHz e)
[ 20.012] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 3040 3080 3300 720 725 730 750 +hsync +vsync (22.5 kHz e)
[ 20.012] (II) modeset(0): Modeline "720x576"x0.0 27.00 720 732 796 864 576 581 586 625 -hsync -vsync (31.2 kHz e)
[ 20.012] (II) modeset(0): Modeline "1440x576i"x0.0 27.00 1440 1464 1590 1728 576 580 586 625 interlace -hsync -vsync (15.6 kHz e)
[ 20.012] (II) modeset(0): Modeline "1440x480i"x0.0 27.00 1440 1478 1602 1716 480 488 494 525 interlace -hsync -vsync (15.7 kHz e)
[ 20.012] (II) modeset(0): Modeline "640x480"x0.0 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e)
[ 20.012] (II) modeset(0): Modeline "800x600"x0.0 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e)
[ 20.012] (II) modeset(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e)
[ 20.013] (--) modeset(0): HDMI max TMDS frequency 300000KHz
I’ve reached the end of what I can troubleshoot on my own, but ChatGPT suggests that it may be “display disconnect/flaky EDID”, “autostart script respawning X blindly”, “wrong resolution forced”. The only thing that makes this deployment different than my others, is that I had to modify the chromium autostart script to get 4K working. Despite supporting 4K, the TV that this Pi is connected to advertises 1080P as its preferred mode. The Pi always wanted to respect the preferred mode (1080) and the only way I found to convince the Pi to persistently output 4K was by modifying the autostart script. See below:
...
#exec "$STARTX" "$FP_CHROMIUM" $CHROMIUM_OPTS "${URL:-https://site.com/}" -- -nocursor
exec "$STARTX" /bin/bash -c "xrandr --output HDMI-1 --mode 3840x2160;
exec $FP_CHROMIUM $CHROMIUM_OPTS '${URL:-https://site.com/}'" -- -nocursor
Your thoughts would be much appreciated 