qemu for arm64 on x86_64 Linux machine

This is just documenting the various points to note, trials, errors etc when I tried to run arm64 on x86_64 using qemu. This post does not have a very satisfactory ending - the VM was far too slow for me to try OpenSpace or OCVWarp or anything else for arm64 tests.

Via bing copilot

https://documentation.ubuntu.com/server/how-to/virtualisation/qemu/index.html#boot-arm64-virtual-machines-on-qemu

https://documentation.ubuntu.com/server/how-to/graphics/gpu-virtualization-with-qemu-kvm/#gpu-virtualization-with-qemu-kvm

general qemu setup 

https://christitus.com/vm-setup-in-linux/

from

https://www.youtube.com/watch?v=Kq849CpGd88

qemu-system-aarch64 \

 -m 2048\

 -cpu max \

 -M virt \

 -nographic \

 -drive if=pflash,format=raw,file=efi.img,readonly=on \

 -drive if=pflash,format=raw,file=varstore.img \

 -drive if=none,file=noble-server-cloudimg-arm64.img,id=hd0 \

 -device virtio-blk-device,drive=hd0 \

 -netdev type=tap,id=net0 \

 -device virtio-net-device,netdev=net0

could not find net0, so tried

without network

---------------

qemu-system-aarch64 \

 -m 2048\

 -cpu max \

 -M virt \

 -nographic \

 -drive if=pflash,format=raw,file=efi.img,readonly=on \

 -drive if=pflash,format=raw,file=varstore.img \

 -drive if=none,file=noble-server-cloudimg-arm64.img,id=hd0 \

 -device virtio-blk-device,drive=hd0 

This went into a loop around 10 minutes in,

[FAILED] Failed to start systemd-resolved.service - Network Name Resolution.

See 'systemctl status systemd-resolved.service' for details.

         Starting systemd-resolved.service - Network Name Resolution...

[FAILED] Failed to start systemd-resolved.service - Network Name Resolution.

See 'systemctl status systemd-resolved.service' for details.

         Starting systemd-resolved.service - Network Name Resolution...

[FAILED] Failed to start systemd-resolved.service - Network Name Resolution.

See 'systemctl status systemd-resolved.service' for details.

         Starting systemd-resolved.service - Network Name Resolution...

[    **] (1 of 2) Job apparmor.service/start running (13min 35s / no limit)

When running virt-manager,

"The emulator may not have search permissions for the path"

First run with sudo and then without?

https://askubuntu.com/questions/722034/permission-error-in-virtual-machine-manager

sudo virt-manager

(say yes when it asks to fix the problem, go to next step, then cancel)

then

virt-manager

That worked.

Chrome remote desktop is an option - 

https://medium.com/@selvamraju007/install-and-launch-ubuntu-22-04-desktop-on-google-cloud-1fba8c0f9585

https://remotedesktop.google.com/?pli=1

But not available for arm64?

Login incorrect

ubuntu login: password[  361.700501] cloud-init[1126]: Cloud-init v. 24.4.1-0ubuntu0~24.04.3 running 'modules:final' at Fri, 09 May 2025 07:42:17 +0000. Up 360.36 seconds.

Password: ci-info: no authorized SSH keys fingerprints found for user ubuntu.

Probably must run

virt-sysprep

https://stackoverflow.com/questions/29137679/login-credentials-of-ubuntu-cloud-server-image

--password ubuntu:password:ubuntu

sets the password ubuntu for the user ubuntu.

virt-sysprep [--options] -a disk.img

https://manpages.ubuntu.com/manpages/trusty/man1/virt-sysprep.1.html

virt-sysprep --password ubuntu:password:ubuntu -a ubuntu2404-arm64.img

sudo apt install libguestfs-tools

virt-customize --password ubuntu:password:ubuntu -a ubuntu2404-arm64.img

virt-customize -a ubuntu2404-arm64.img  --password ubuntu:password:ubuntu

Extra parameter on the command line: ‘ --password’.

Try ‘virt-customize --help’ or consult virt-customize(1) for more information

Needed to run as sudo.

sudo virt-customize -v -x -a ubuntu2404-arm64.img --root-password password:password

Boots up in around 5 minutes.

Increase size of disk

https://computingforgeeks.com/how-to-extend-increase-kvm-virtual-machine-disk-size/

sudo qemu-img resize /home/sssvv/Downloads/QEMU/noble-server-cloudimg-arm64.img +20G

qemu-img: Command not found: resize /home/sssvv/Downloads/QEMU/noble-server-cloudimg-arm64.img +20G

maybe needs converting to raw?

https://bobcares.com/blog/qemu-img-error-resizing-image-invalid-argument/

Jenkins and Github

 I was curious to know how Jenkins CI/CD works with Github, similar to what is seen on the OpenSpace repository. So one way is to use webhooks, as detailed in this guide,

Complete Step-by-Step Jenkins CICD with GitHub Integration | by Mudasir | Medium

bash: cannot execute: required file not found

bash: cannot execute: required file not found

The problem, it turned out, was an incorrect path in the shebang.

#!/bin/bash

echo "Hello, World!"

will fail on a machine which does not have bash at /bin (or a link to bash there). I believe cron jobs also have problems if the shebang does not directly point to bash? Anyway, we can always do a 

which bash

to find the correct path and enter it in the shebang.

download just one directory from github repository

 Via 
https://stackoverflow.com/questions/7106012/download-a-single-folder-or-directory-from-a-github-repository

https://downgit.github.io/

for using 

https://github.com/hn-88/android-ndk-samples/tree/main/hello-libs

in

https://github.com/hn-88/OpenCV-android-samples/

virtualizing Raspberry Pi on an iPad with UTM

 We can virtualize a Raspberry Pi with UTM, but need old 32 bit version, since 64 bit is broken on UTM, tho' QEMU works - 

https://github.com/utmapp/UTM/issues/4827

script to run multiple commands on a remote server over ssh

 Made Chatgpt write the following script. The EOF syntax is useful. In our case, we need to put in the appropriate -pPORT also.

write a bash shell script to ssh into two servers server1 and server2 with ssh keys key1.pem and key2.pem, run sudo apt upgrade on both, and show the result on the terminal.

#!/bin/bash

# Define servers and keys

SERVER1="user1@server1"

KEY1="key1.pem"

SERVER2="user2@server2"

KEY2="key2.pem"

# Function to upgrade a server

upgrade_server() {

  local SERVER=$1

  local KEY=$2

  echo "Upgrading packages on $SERVER..."

  

  ssh -i "$KEY" -o StrictHostKeyChecking=no "$SERVER" << 'EOF'

    echo "Running apt update..."

    sudo apt update

    echo "Running apt upgrade..."

    sudo DEBIAN_FRONTEND=noninteractive apt upgrade -y

EOF

}

# Upgrade both servers

upgrade_server "$SERVER1" "$KEY1"

echo "---------------------------------------------"

upgrade_server "$SERVER2" "$KEY2"

x86 Emulation on iPad with UTM

Continuing my earlier post about UTM - finally got JIT to work on iPad. Apparently I had been successful earlier also, but had thought that the QEMU error was due to JIT not being enabled. Going into settings (in the context menu of each VM, accessed by long-press) and trying to increase RAM, UTM gave the warning that the system had only 1700 MB of RAM left, of which 1300 or so was free, hence increasing the VM's RAM beyond this would cause crashes. Ubuntu 14.04 boots up in around 4 minutes. Unfortunately, maybe due to Ubuntu's behaviour when running on a display without acceleration, very slow to respond. Nearly a minute for keystrokes to appear on screen!

What I followed was this:

Installed AltStore via AltServer for Windows - https://faq.altstore.io/altstore-classic/how-to-install-altstore-windows

Installed StikJIT & StosVPN via AltStore - StikJIT user manual

https://github.com/StephenDev0/StikJIT/blob/main/user-manual.md

Copied over the pairing file created as per the user manual above, using iCloud Drive (Installed that also on the Windows machine.)

Then, the procedure is - 

• Swipe up from down and hold, to show all applications - swipe up applications which you want to close and start again with JIT, like UTM.
• Start StosVPN, click to start the connection
• Start StikJIT - one-time requirement of passing on the path to the pairing file, then
• Click Enable JIT - a few moments later, it prompts for which app to enable JIT for, from a list of apps - choose UTM, and then UTM opens up with JIT enabled. Can start up JMs at this point. 

But as mentioned in the first paragraph of this post, we need to choose those VM images (or create such VMs) which can work with 512 MB or 768 MB of RAM on this 9th gen iPad, since it has limited free RAM. Perhaps trying Raspberry Pi might be a good option.

monitoring websites for changes - followthatpage

 There was a request from one of my colleagues for suggestions - he wanted a tool to automatically let him know when some particular websites had changes. Something similar to an RSS feed for a website which doesn't have an RSS feed, I guess. 

I replied that I use

https://www.followthatpage.com/

to monitor up to 20 pages for free per account per day - so if you don't want daily checks, you can add more pages, too.

There are many other "freemium" and paid options, too. 

development for Android / iOS - preliminaries

Seeing that the mobile devices were quite competitive with the desktop's processing power in a previous post, thought about working on porting various tools like OCVWarp to Android and iOS if feasible.

OpenCV Android - had earlier cloned / forked NDK samples.

OpenCV for iOS - samples are at https://github.com/opencv/opencv_for_ios_book_samples

https://docs.opencv.org/4.11.0/d3/dc9/tutorial_table_of_content_ios.html

The binaries are available here 

https://sourceforge.net/projects/opencvlibrary/files/opencv-ios/

only up to OpenCV v3.4.3, but iOS framework seems to be available at

https://sourceforge.net/projects/opencvlibrary/

and

https://github.com/opencv/opencv/releases/tag/4.11.0

To check if swift playgrounds is available on 9th gen ipad - https://www.theverge.com/2021/6/15/22534902/ipad-pro-apple-swift-playgrounds-4-wwdc-2021

To check if example opencv apps can run on ipad.

info about various ARM platforms

 https://www.baeldung.com/linux/arm64-armel-armhf-overview

So, arm64 is sometimes referred to as aarch64. But the github arm64 appimage builds are not compatible with Ubuntu on raspberry pi 4 etc, maybe because of library differences, since the github runners are Ubuntu 24.04. 

simple logger created by chatgpt

I wanted to make a simple load-average logger. Thought of making ChatGPT do the typing, instead of me creating the simple code.

The result was quite OK.

https://github.com/hn-88/GSheetLoadLogger

The prompts and conversation are in the issues tab.

moving Virtualbox VMs to external drive

VirtualBox Manager
> Right-click on the VM
> Select "Move"
> Choose the new location and click "Move"

(Tho' the progress bar doesn't seem to work, it moved the VM and associated files to the external drive in approx the usual time it would take for a 12 GB file move.)

OCVWarp AppImage won't run on Raspberry Pi

The OCVWarp AppImage compiled on github's ARM64 runner will not run on Raspberry Pi 4, error screenshot below.

But OCVWarp runs when compiled on the Pi itself.

( 

In hindsight, 

This might be a problem with 
(a) /tmp not allowing executable permissions
(b) the ld-linux-aarch64.so not having executable permissions
)

Google's "free to try" AI Studio

Google AI Studio has image generation, video generation and more, in addition to text chat. But even Google's Gemini does not know this:) 

Unless we enable "auto-save" in the settings (I guess) our prompts are not saved in History.

Choosing the model Gemini2.0 Flash (image generation)

"Create an image of a sunset over a sandy beach" - result is below.

Not bad.

By clicking the Video generation tab, Veo 2 generated the following videos on the respective prompts. Not very good, but it's a good start. And the best part is that it's free. And it took less than a minute to generate.

"Create a video of overcast clouds over sunset on a sandy beach" - resulted in a timelapse-style video below:

"Generate a 360 degree equirectangular video of sunset over a beach" resulted in:

Since this was not really an equirectangular 360 degree video, tried by running the same prompt again. Then it gave:

 Refining my prompt, changed it to "Generate a VR360 equirectangular video of sunset over a beach" which resulted in this:

I didn't want any human beings or birds in the video, so I tried adding a negative prompt of birds, men, women - and the same prompt as above. But the result still had this woman,

All right. Maybe it will do better when given an image to work with. So, I uploaded the sunset image earlier generated with Gemini 2.0 Flash, and gave the prompt "Generate a VR360 equirectangular video from this image by panning left to right."

But it did not pan, instead added birds!

In summary, a long way to go. But since it's fast and free (the video generation did not specify any queries per day limits, but the Gemini models did specify 1500 requests per day and so on in the free tier), we can definitely try out some stuff. And perhaps upscale locally or with google colab. 

Geekbench scores - Android phone, iPad, laptop, desktop, Raspberry Pi

Thought of doing some benchmarks to rate the performance of the various devices to which I have access. Samsung Galaxy M34 Android phone, Raspberry Pi 4 8 GB without cooling fan, i5-4430 processor desktop with GTX 1050 graphics card, i5-1235U processor laptop with Intel graphics, 9th gen iPad.

https://www.geekbench.com/download/

Higher scores are better.

https://www.geekbench.com/download/linux/

Example benchmarks also linked in the page above.

CPU single-core / multi-core - the Android phone was surprisingly close to the desktop. The iPad crashed this test, so I've not added it in the lineup below. The pi overheated without the cooling fan, hence it gave a worse multi-core performance than could be possible with better cooling.

Pi4 (292/519) < M34 (960/2072) < Desktop (1062/2813) < Laptop (2131/7460)

GPU OpenCL / Vulkan - the Pi4 gave an error, unknown CL platform, so it is not listed below. But the Pi5 seems to have a rating of only 96! And the iPad perhaps outperformed the Laptop.

M34 (2306/2339) < Laptop (11723/15237) < iPad (13914 (Metal)) < Desktop (22555/NA)

Conclusion - The Raspberry Pi 4 did much worse than I expected, and the mobile devices - the phone and the iPad - did better than I expected. 

Ubuntu using userland on Android

Trying out UserLAnd - https://userland.tech/features

via https://www.geeksforgeeks.org/linux-on-android/

Rs. 190 to buy pro version.

Downloaded 80 MB, on 5G took less than 2 minutes.

Setting up file system - another 2 minutes, then came up without any browser or remote desktop.

Find ip address from Android settings > Wifi > Connection > scroll down to Details.

Port is 5951, Via

https://github.com/CypherpunkArmory/UserLAnd/issues/1133

xtightvncviewer

VNC pw is found via Filesystem > long press on "apps" > Edit 

sudo apt update

Reading package lists... Error!

W: Unable to read /etc/apt/sources.list - RealFileExists (38: Function not implemented)

sudo apt-get update

works

sudo apt-get upgrade

says 204 packages to be upgraded.

Connection failed, since vnc was being upgraded.

ssh with username=userland did not work over the network on port 22, but worked OK on localhost.

Problems when trying to install a browser - 

Preparing to unpack .../firefox_1%3a1snap1-0ubuntu2_arm64.deb ...

debconf: unable to initialize frontend: Dialog

debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 78.)

debconf: falling back to frontend: Readline

=> Installing the firefox snap

==> Checking connectivity with the snap store

===> System doesn't have a working snapd, skipping

Unpacking firefox (1:1snap1-0ubuntu2) ...

Setting up firefox (1:1snap1-0ubuntu2) ...

update-alternatives: using /usr/bin/firefox to provide /usr/bin/gnome-www-browser (gnome-www-browser) in auto mode

update-alternatives: using /usr/bin/firefox to provide /usr/bin/x-www-browser (x-www-browser) in auto mode

Command '/usr/bin/firefox' requires the firefox snap to be installed.

Please install it with:

snap install firefox

 sudo apt-get install snapd

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

snapd is already the newest version (2.67.1+22.04).

 sudo snap install firefox 

error: cannot communicate with server: Post "http://localhost/v2/snaps/firefox": dial unix /run/snapd.socket: connect: no such file or directory

snap install firefox

error: cannot communicate with server: Post "http://localhost/v2/snaps/firefox": dial unix /run/snapd.socket: connect: no such file or directory

via

https://packages.debian.org/sid/arm64/firefox/download

 wget http://http.us.debian.org/debian/pool/main/f/firefox/firefox_137.0.2-1_arm64.deb

sudo dpkg -i firefox*.deb

Selecting previously unselected package firefox.

(Reading database ... 59497 files and directories currently installed.)

Preparing to unpack firefox_137.0.2-1_arm64.deb ...

Unpacking firefox (137.0.2-1) ...

dpkg: dependency problems prevent configuration of firefox:

 firefox depends on libasound2t64 (>= 1.0.16); however:

  Package libasound2t64 is not installed.

 firefox depends on libatk1.0-0t64 (>= 1.12.4); however:

  Package libatk1.0-0t64 is not installed.

 firefox depends on libc6 (>= 2.39); however:

  Version of libc6:arm64 on system is 2.35-0ubuntu3.9.

 firefox depends on libevent-2.1-7t64 (>= 2.1.8-stable); however:

  Package libevent-2.1-7t64 is not installed.

 firefox depends on libglib2.0-0t64 (>= 2.38.0); however:

  Package libglib2.0-0t64 is not installed.

 firefox depends on libgtk-3-0t64 (>= 3.13.7); however:

  Package libgtk-3-0t64 is not installed.

 firefox depends on libnss3 (>= 2:3.109~); however:

  Version of libnss3:arm64 on system is 2:3.98-0ubuntu0.22.04.2.

 firefox depends on libvpx9 (>= 1.12.0); however:

  Package libvpx9 is not installed.

 firefox depends on libxcomposite1 (>= 1:0.4.6); however:

  Version of libxcomposite1:arm64 on system is 1:0.4.5-1build2.

dpkg: error processing package firefox (--install):

 dependency problems - leaving unconfigured

Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...

Processing triggers for hicolor-icon-theme (0.17-2) ...

Processing triggers for man-db (2.10.2-1) ...

Errors were encountered while processing:

 firefox

via

https://ubuntu.pkgs.org/20.04/ubuntu-updates-main-arm64/firefox_136.0+build3-0ubuntu0.20.04.1_arm64.deb.html

userland@localhost:~$ sudo dpkg -i firefox*.deb

dpkg: warning: downgrading firefox from 137.0.2-1 to 136.0+build3-0ubuntu0.20.04.1

(Reading database ... 59587 files and directories currently installed.)

Preparing to unpack firefox_136.0+build3-0ubuntu0.20.04.1_arm64.deb ...

Unpacking firefox (136.0+build3-0ubuntu0.20.04.1) over (137.0.2-1) ...

dpkg: warning: unable to delete old directory '/usr/share/firefox/distribution': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser/defaults/preferences': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser/defaults': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser/chrome/icons/default': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser/chrome/icons': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser/chrome': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox/browser': Directory not empty

dpkg: warning: unable to delete old directory '/usr/share/firefox': Directory not empty

dpkg: dependency problems prevent configuration of firefox:

 firefox depends on libgdk-pixbuf2.0-0 (>= 2.22.0); however:

  Package libgdk-pixbuf2.0-0 is not installed.

dpkg: error processing package firefox (--install):

 dependency problems - leaving unconfigured

Processing triggers for desktop-file-utils (0.26-1ubuntu3) ...

Processing triggers for hicolor-icon-theme (0.17-2) ...

Processing triggers for man-db (2.10.2-1) ...

Errors were encountered while processing:

 firefox

sudo apt-get install  libgdk-pixbuf2.0-0

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

You might want to run 'apt --fix-broken install' to correct these.

The following packages have unmet dependencies:

 libgdk-pixbuf2.0-0 : Depends: libgdk-pixbuf-xlib-2.0-0 (>= 2.40.2-2build4) but it is not going to be installed

E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution).

userland@localhost:~$ sudo apt-get install  libgdk-pixbuf     

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

E: Unable to locate package libgdk-pixbuf

userland@localhost:~$ sudo apt --fix-broken install

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

Correcting dependencies... Done

The following additional packages will be installed:

  firefox

The following packages will be upgraded:

  firefox

1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

1 not fully installed or removed.

Need to get 72.3 kB of archives.

After this operation, 248 MB disk space will be freed.

Do you want to continue? [Y/n] 

Get:1 http://ports.ubuntu.com/ubuntu-ports jammy/main arm64 firefox arm64 1:1snap1-0ubuntu2 [72.3 kB]

(which again fails due to snap being broken.)

via

https://www.omgubuntu.co.uk/2022/04/how-to-install-firefox-deb-apt-ubuntu-22-04

https://support.mozilla.org/en-US/kb/install-firefox-linux#w_install-firefox-deb-package-for-debian-based-distributions

firefox

[Parent 32675, Main Thread] WARNING: read-only dup failed (Permission denied); not using memfd: file /builds/worker/checkouts/gecko/ipc/glue/SharedMemory_posix.cpp:218

[GFX1-]: glxtest: ManageChildProcess failed

[GFX1-]: No GPUs detected via PCI

[32675] Sandbox: Couldn't open video device /dev/video215

[32675] Sandbox: Couldn't open video device /dev/video102

[32675] Sandbox: Couldn't open video device /dev/video9

[32675] Sandbox: Couldn't open video device /dev/video8

[32675] Sandbox: Couldn't open video device /dev/video155

[32675] Sandbox: Couldn't open video device /dev/video11

[32675] Sandbox: Couldn't open video device /dev/video216

[32675] Sandbox: Couldn't open video device /dev/video6

[32675] Sandbox: Couldn't open video device /dev/video214

etc

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

[GFX1]: no fonts - init: 1 fonts: 14 loader: 0

etc

firefox opens, but all tabs crash.

Gah - your tab just crashed.

(Then it crashes the userland ubuntu also.)

sudo apt-get epiphany-browser

(package name via software manager on desktop)

Trying to run OCVWarp ARM64AppImage on the userland ubuntu,

did install fuse with

sudo apt-get install libuse2

but

fuse: failed to open /dev/fuse: Permission denied

Cannot mount AppImage, please check your FUSE setup.

https://docs.appimage.org/user-guide/troubleshooting/fuse.html

 sudo modprobe -v fuse

bash: line 1: modprobe: command not found

 squashfs-root/AppRun

GST_PLUGIN_SCANNER=

GST_PLUGIN_SYSTEM_PATH=/home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/lib/aarch64-linux-gnu/gstreamer-1.0

GST_PLUGIN_PATH=/home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/lib/aarch64-linux-gnu/gstreamer-1.0

squashfs-root/AppRun: 101: exec: /home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/usr/lib/ld-linux-aarch64.so.1: Permission denied

sudo  squashfs-root/AppRun

GST_PLUGIN_SCANNER=

GST_PLUGIN_SYSTEM_PATH=/home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/lib/aarch64-linux-gnu/gstreamer-1.0

GST_PLUGIN_PATH=/home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/lib/aarch64-linux-gnu/gstreamer-1.0

squashfs-root/AppRun: 101: exec: /home/userland/Downloads/OCVWarp-4.01/build/squashfs-root/usr/lib/ld-linux-aarch64.so.1: Permission denied

sudo apt-get install epiphany-browser 

running the above from vnc would crash.

run from ssh on local shell, installed 100+ MB of dependencies.

epiphany-browser  

** (epiphany:2707): WARNING **: 04:54:34.367: Disabled hardware acceleration because GTK failed to initialize GL: No GL implementation is available.

** (epiphany:2707): WARNING **: 04:54:34.400: WebKitWebContext:use-system-appearance-for-scrollbars property is deprecated and does nothing

** (epiphany:2707): WARNING **: 04:54:34.526: WebKitWebContext:use-system-appearance-for-scrollbars property is deprecated and does nothing

** (epiphany:2707): WARNING **: 04:54:35.209: webkit_settings_set_enable_dns_prefetching is deprecated and does nothing.

bwrap: Can't read /proc/sys/kernel/overflowuid: Permission denied

** (epiphany:2707): ERROR **: 04:54:35.657: Failed to fully launch dbus-proxy: Child process exited with code 1

Trace/breakpoint trap

And using qemu, once again, likely to be too slow - 

https://virtualmachinery.weebly.com/operating-systems.html

(on ipad, ubuntu was taking 30 minutes+ to boot up.)

So, I could try the ARM64 OCVWarp on raspberry pi instead. (which won't work out of the box, may need to compile on the Pi, since Raspberry Pi may use a different architecture compared to the github ARM64 runner - https://linuxvox.com/blog/what-is-difference-between-arm64-and-armhf/ .)

airtel's horrendous "AI" customer service

I was trying to recharge another prepaid Airtel number with "international roaming plan 2997" for 365 day validity.

Tried with Airtel thanks app from my Airtel mobile - failed.

Tried from website - failed.

Tried calling customer care - they said try going to a shop.

Tried from shop - failed.

Tried sending them an email to 121@in.airtel.com - "We noticed that you're contacting us from an email ID that isn't linked to your Airtel account. 

You shall write back to us from your registered ID or reach out to airtel thanksapp get instant support 24x7 right from the help and support section."

The help and support section is a chatbot. There didn't seem to be any option to contact a human being. 

Finally, I thought maybe trying from the Airtel app on the actual prepaid account for which Intl. Roaming was needed - success. Edit - half an hour later, that transaction was reversed, too!  

Airtel's own customer service people did not know this, the shop guys (tried two different shops) did not know this, it is not mentioned anywhere that these intl. roaming plans need to be bought from the phone which is actually going to roam! 

UTM for OpenSpace on iOS / MacOS

Found on https://getutm.app/faq/#what-are-the-limitations

"The lack of hardware virtualization on Apple A-chips means that even for ARM code we must re-compile it with JIT. Therefore performance would never reach the levels possible with KVM. There is also no support for GPU virtualization so that means no DirectX or OpenGL. This makes most modern games non-playable." So, OpenSpace is most probably not suitable to run via UTM on iPad / iOS.

More about JIT - https://faq.altstore.io/altstore-classic/enabling-jit/altjit

Found on https://mac.getutm.app/

"UTM does not currently support GPU emulation/virtualization on Windows and therefore lacks support for 3D acceleration (e.g. OpenGL and DirectX). You may be able to run older games with software rendering options, but nothing with hardware acceleration. There is experimental support for hardware OpenGL acceleration on Linux through Virgl."

So, OpenSpace on Ubuntu might be doable - at least with performance similar to a Windows box without NVidia graphics - on a Mac with UTM.

---------------------------

Details of what didn't work

Found the limitations the hard way, trying for many hours on the (9th gen) iPad (since I don't have access to a Mac at the moment). 

UTM SE - with no JIT - took half an hour or more to boot Ubuntu 14.04 (that's not a typo, it really was the old version 14.04)

Trying to enable JIT - 

Directly on AltStore - need a Hackintosh or Mac for it? - https://github.com/altstoreio/AltStore/issues/1349

Jitstreamer-EB - https://jkcoxson.com/jitstreamer

says use stikJIT - https://stikdebug.xyz/

StikJIT user manual

https://github.com/StephenDev0/StikJIT/blob/main/user-manual.md

Apparently enabling JIT is a one-time installation - https://faq.altstore.io/altstore-classic/enabling-jit

We can't use Altstore PAL since we're not in the EU - tried and failed.

To install a downloaded ipa, go to Altstore > My apps (at the bottom), and click the + on the top. The ipa should be visible. 

(if ipa is not visible, we may need to navigate using the files app, and "open with" Altstore.

Then, it asks for apple creds.)

Transferred the pairing file using icloud drive.

Long press on UTM, then "enable jit", then try to open the vm, then

error trying to connect to spice server.

If StosVPN is turned off, then AltJIT not found, can't run VMs without JIT.

FAILED TO CONNECT TO SPICE

https://github.com/utmapp/UTM/discussions/6362

To force quit, 

swipe up and hold to open app switcher, then swipe up on the app to force-quit it.

Jitstreamer EB on Debian guide is here,

https://github.com/jkcoxson/JitStreamer-EB/blob/master/install-docs/jitstreamer-eb-debian-docker-instructions.md (not yet tried this.)

To try - minimal Ubuntu or something like that without 3d acceleration, which may not need spice.

debian 11 ARM64 lxde with spicetools installed, from gallery.

It was a zip file. Open in Downloads > unzipped. Long press and open in UTM.

But same error, QEMU exited no error message.

UTM also says Virtualization is not supported on your device.

So we can only use Emulate.

Still, same error. Then, I tried UTM SE, which took half an hour to boot the old version of Ubuntu as noted at the top of this post.

cloudflare plugin for certbot

Found this option, 

--dns-cloudflare      Obtain certificates using a DNS TXT record (if you are using Cloudflare for DNS). (default: False)

from

https://eff-certbot.readthedocs.io/en/stable/man/certbot.html

And documentation for this plugin is at

https://certbot-dns-cloudflare.readthedocs.io/en/stable/index.html

(example invocation at end)

and how to install plugin is 

sudo apt-get -y install python3-certbot-dns-cloudflare

https://installati.one/install-python3-certbot-dns-cloudflare-ubuntu-20-04/

automating backup with python - rclone and google drive

There was a python script written to

1. Compress the audio files that are created from the previous backup date to now into a folder and zip it 

2. Export the zip file to Gdrive.

2. Extract the mysql backup into a .sql file, export that also into the gdrive folder.

3. delete the past backups. 

For this, rclone and zip needed to be installed. After that, I passed on abbreviated instructions for setting up an rclone remote for GDrive - 

You will need to use the method "(N) running rclone on a machine without web browser" from the instructions onscreen, which are also shown at

https://rclone.org/drive/

As mentioned here, 

https://hnsws.blogspot.com/2022/11/rclone-and-out-of-band-flow.html

you need to download the latest rclone and install on your local system (where you have access to a web browser, where you can log on to google and give permission for rclone etc when prompted), and follow the onscreen instructions to set up rclone config for your desired google drive login.

After they set up the script, remote etc and found them working, set up a daily cron for 12:15 midnight,

15 0 * * Sun /usr/bin/python3 /home/path-to/backup_service.py 

which the user can edit from their login using

crontab -e

migrating web servers and associated scripts using rclone copy

As mentioned in the previous post, our server migration involved consolidating a web server into a DB server - we chose this method, since cloning the DB server was quick, while export followed by import of MySQL databases takes quite a bit longer as noted in the earlier 2024 migration post.

Copied the ssh private key for the destination server to the source server, and created an rclone remote using SFTP to the destination server. 

zip -r -q webserver1.zip /path/to/webserver/files

(repeated this for all the web server directories later)

rclone copy webserver1.zip rcloneremote:/home/azureuser

(repeated this for all the other zip files later)

From the destination server,

unzip webserver1.zip

cd path/to/webserver/

sudo mv files /path/to/webserver

cd /path/to/webserver

sudo chown -R azureuser:www-data .

sudo chmod -R 775 .

----------------------------------------------

Then, the apache config files - 

sudo zip -r -q etcapache.zip /etc/apache2

(rclone copy etc, and change ownership to root)

and the letsencrypt certificates etc,

sudo zip -r -q etclets.zip /etc/letsencrypt

(rclone copy etc, and change ownership to www-data for the file/directory which it needs, and the others to root)

-----------------------------------------------

With these, the files to be copied for the web servers were done. And I could start them up - 
sudo a2ensite webserver1
sudo systemctl reload apache2
etc.

Also needed were

• installing all the necessary apache and php modules - which I had done earlier using the steps at the 2024 migration post.
• installing restic for backups as per the backups section of that post.
• rclone copy, individually, for the .sh backup scripts and the notifier directory.
• Copy-pasting lines from .config/rclone/rclone.config  as noted in the restic backup script - the rclone config was modified by copy pasting the extra remotes from source to destination.
• Copy-pasting cron jobs from both crontab -e and sudo crontab -e
• Setting up postfix with gmail smtp as mentioned at this post for which 
  sudo apt remove ssmtp
  sudo apt install mailutils postfix
  and then editing the conf files was required.

-----------------------------------------------

Then, we had awstats running, so 

sudo zip -r -q etcawstats.zip /etc/awstats

for the config files, and

sudo apt install awstats

with editing out the cron which is auto installed at
sudo nano /etc/cron.d/awstats

and then copying across the awstats data - the DataDir was set to this directory -  

sudo zip -r -q varlibawstats.zip /var/lib/awstats

(then rclone copy, then unzip on the destination machine, move and set appropriate permissions etc) 

----------------------------------------------------

Tested the backup and load alert notification scripts, checked awstats the next day to verify that the stats were updating correctly.

------------------------------------------------------

Edit: one week later - some more configurations which were missed out.

sudo apt install certbot python3-certbot-apache

sudo certbot --apache

This was sufficient to enable auto-updates for the letsencrypt SSL certificates which had been copied over from the old server.

On another server, onto which we had migrated a single domain, but which already had other active letsencrypt SSL encrypted websites,

sudo certbot --cert-name subdomain.ourdomain.org

for renewing only this one, without disturbing the others.

For removing a certificate later, we can use

certbot delete --cert-name example.com

[so you will need to know the exact cert-name - not the specific FQDN(or domain name) within the cert]

[you can get the cert names with: certbot certificates]

https://community.letsencrypt.org/t/how-do-i-remove-a-certificate/121475

-----------------------------------------------------------

One of the Moodle instances gave an error, Adhoc task failed: assignfeedback_editpdf\task\convert_submission,The configured path to ghostscript is not correctly set: The ghostscript path points to a non-existent file

Solution was to install ghostscript,
sudo apt install ghostscript

--------------------------------------------------------

Then the php max_file_upload also had to be modified according to this earlier post, https://hnsws.blogspot.com/2021/03/some-post-install-changes-needed-for.html

sudo nano /etc/php/8.3/apache2/php.ini

( Ctrl+w to find and change post_max_size

Ctrl+w to find and change upload_max_filesize

Ctrl+w to find and change max_execution_time  - set to 600 for now.)

sudo systemctl restart apache2

and also did the same for /etc/php/8.3/cli/php.ini

-----------------------------------------------------------

When upgrading a plugin, a warning was shown that php extension soap was not installed, and that update will continue only after it is installed. So,

sudo apt install php-soap

-------------------------------------------------------------

Edit - a few days later - 

https://linuxize.com/post/how-to-change-hostname-on-ubuntu-22-04/

sudo hostnamectl

sudo hostnamectl set-hostname our-desired-hostname

-------------------------------------------------------------

Then, a warning while updating a plugin - max_input_vars must be at least 5000

sudo nano /etc/php/8.3/apache2/php.ini

sudo nano /etc/php/8.3/cli/php.ini

sudo systemctl restart  apache2

-------------------------------------------------------------

migrating Azure VM from one tenant to another

Azure documentation talks about migrating a VM from one region to another region - https://learn.microsoft.com/en-us/azure/resource-mover/tutorial-move-region-virtual-machines

https://argano.com/insights/articles/microsoft-azure-clone-vm-how-to-clone-a-vm-in-azure.html

(this seems to be within same tenant)

But we wanted to shift from one tenant to another. Following this post, 
https://medium.com/@morsi.masmoudi/complete-guide-to-cloning-and-moving-a-vm-from-one-azure-tenant-to-another-8fa65dd6955a

but with some changes - instead of a file share, creating a disk from snapshot seems to need a blob container for the "Create Managed Disk" applet nowadays. Following the exact steps as above results in not finding any container in that storage account.

Shifted using the following steps:

1. Enabled CLI maintenance mode on the Moodle instances with 
sudo -u www-data /usr/bin/php admin/cli/maintenance.php --enable
- verified that this does stop the cron also, which would otherwise hit the database every minute.

2. Shut down the database VM, went to its OS disk, created snapshot, went to the snapshot's page, "Export snapshot", copied the export snapshot url. 

3. I had earlier created a test VM in the destination tenant, in the Central India region which is the cheapest at present. Had also created a storage account, and a blob container. Also, had installed azcopy on that VM with the following - https://www.thomasmaurer.ch/2019/05/how-to-install-azcopy-for-azure-storage/

#Download AzCopy

wget https://aka.ms/downloadazcopy-v10-linux

 

#Expand Archive

tar -xvf downloadazcopy-v10-linux

 

#(Optional) Remove existing AzCopy version

sudo rm /usr/bin/azcopy

 

#Move AzCopy to the destination you want to store it

sudo cp ./azcopy_linux_amd64_*/azcopy /usr/bin/

4. Created SAS token (Shared Access Signature) from Azure portal > thestorageaccount - the default 3600 seconds may be too short if we need to do multiple operations. Enabled container, blob and file, all three, and copied the blob url and sas token strings. The blob url would be of the form https://storageaccountname.blob.core.windows.net/?sv=SAS-token - we need to edit this, and add nameofourcontainer/desired-name-of-file.vhd before the ?sv=SAS-token

5. SSH'd into that VM, and ran azcopy. (I could have avoided creating the VM, installing azcopy etc by using an Azure shell instead.) The command will be of the form:

azcopy copy "https://md-abcefg12nmg.z12.blob.storage.azure.net/snapshot/abcd?sv=2018-03-28&sr=b&si=this-is-the-snapshot-url-1234566b61d3&sig=zj9jh0ABCDEDFGHHJtnkD9yK0rvJ44I%3D" "https://lmsmigratestorage.blob.core.windows.net/testcontainer/LMSDBsnapshot.vhd?sv=2024-11-04&ss=bfqt&srt=sco&sp=abcdefghytfx&se=2025-04-21T11:49:12Z&st=2025-04-20T03:49:12Z&spr=https&sig=qwertyuiopasdfghjkABCDEFGuLYlgBQlWZE%3D"

# Actually ran steps 2 and 5 three times, azcopy took the following times:

# Elapsed Time (Minutes): 2.034 <-- LMS db OS disk

# Elapsed Time (Minutes): 1.2004 <-- LMS php disk

# Elapsed Time (Minutes): 22.0734 <-- LMS data disk
 

6. From Azure portal, in the destination tenant, Home > Create > Managed Disks > (Choosing Source as Blob storage) > Browse > choosing our VHD snapshot file in blob storage. Creating disk from snapshot, creating snapshot etc are very fast operations, these operations complete in less than a minute.  

7. From the created disk, if it is an OS disk, Create VM. Note that in our case, the default "Operating System type" was v1, but our original VM was v2, so I created the new VM also as v2. 

8. The data disk can be attached later to the VM, even when it is running - "Attach existing disk". Caution - attaching an OS disk as data disk does not seem to work properly - that new OS disk becomes the primary OS disk! 

9. In our case, we were cloning the db VM and copying the php files (and postgresql db) from the php server into the db VM, since we wanted to consolidate the two VMs into a single one. So, I had to copy over from the old VM to the new VM using rclone copy. What I needed to copy, and the steps taken, will be a separate post.

(What does not work:

1. "Export disk" and trying to use that using azure cli - this will not work. We need to create a snapshot first, then export the snapshot, and use the snapshot to re-create the disk in the new tenant.

2. Mounting azure blob storage on a VM and using wget to copy the snapshot VHD to blob storage will not help us to create the disk in the new tenant - azcopy is mandatory.

3. wget -O mydisksnapshot.vhd "https://snapshot-export-URL" followed by
azcopy copy mydisksnapshot.vhd "https://blob-storage-url" will work, but takes double the time - azcopy works fine directly from snapshot url to blob storage url. Caveat is that we must make a container first, and then use azcopy copy.) 

clearing up after docker

 Via https://stackoverflow.com/questions/76833923/safe-way-to-clean-var-lib-docker

/var/lib/docker was using up 16 GB. 

sudo docker system prune --all --volumes

WARNING! This will remove:

  - all stopped containers
  - all networks not used by at least one container
  - all anonymous volumes not used by at least one container
  - all images without at least one container associated to them
  - all build cache

Total reclaimed space: 7.794GB

installed an alarm applet

 On Linux Mint running Xfce, via https://forums.linuxmint.com/viewtopic.php?f=47&t=191832

Installed via Software Manager.

KAlarm needed to download 400 MB! So, instead chose Alarm-clock-applet which was only 563 kB. Shows up in the Applications menu as Alarm Clock. Can set time or timer.

postgres restore from backup - 2 minutes

A quick note on time taken - 

Install and config - 

as per

https://hnsws.blogspot.com/2024/10/moving-multiple-moodle-instances-from.html

which links to

https://documentation.ubuntu.com/server/how-to/databases/install-postgresql/index.html

rclone config

then rclone copy

rclone copy *.sql remotename2024:/home/theuser

psql -h 127.0.0.1 -U username -d databasename < dbdump-noowner.sql -W ThePassWord

This took just two minutes.

decided not to migrate Moodle from MySQL to Postgres

Though Moodle is believed to have better performance on PostgreSQL than on MySQL, 

There is a migrate tool

https://bobcares.com/blog/moodle-mysql-to-postgres/

But could have issues,

Some troubles you may find when using this tool:

If there is any object in the current database (columns, tables,...) not included in the XMLDB schema or the other way around the dbtransfer won't be executed until these objects are removed (this may happen if Moodle has been upgraded from earlier versions, if some plugin hasn't been correctly uninstalled...).

https://docs.moodle.org/405/en/Database_transfer

Also, "Depending on the size of your database, the process may take several hours."

So, decided not to migrate to Postgres at the moment.

Edit - update in Aug 2026 - ChatGPT says, (private URL for my reference - https://chatgpt.com/c/6a9267b3-5d78-83ee-9bed-f3db27750248 ) "My current assessment is that a PostgreSQL migration before the Moodle 5.3 upgrade is unlikely to deliver enough performance improvement to justify the migration effort and testing risk. I'd spend the effort on caching, PHP tuning, and perhaps a RAM upgrade first."

Change	Expected impact
MySQL → PostgreSQL	0–10%
MySQL tuning	5–20%
Redis/MUC tuning	10–50%
Faster CPU	Often noticeable
More RAM (8 → 16 GB)	Often more useful than DB migration

moving a MySQL database from one host to another

We had earlier moved a Moodle install from one server to another, and now wanted to move its database also to localhost.

Using this to set up mysql, creating database + user, and later testing a connection - 

https://www.digitalocean.com/community/tutorials/how-to-install-lamp-stack-on-ubuntu#step-2-installing-mysql

sudo mysql -p worked for logging in as root user.

create database our_master_db;

CREATE USER 'our_db_admin'@'%' IDENTIFIED BY 'OurPassword';

GRANT ALL ON our_master_db.* TO 'our_db_admin'@'%';

https://hnsws.blogspot.com/2024/10/moving-multiple-moodle-instances-from.html#dbs

to export and restore dbs.

date; mysql -h 127.0.0.1 -u our_db_admin -p our_master_db < our_master_db.OldServerdb-2024.15-04-2025.sql; date

This showed that it completed in some 20 minutes. After that, needed to change the connection settings and port in Moodle's config.php

resize OS disk for Azure VM

Wanted to resize one of our Azure VM OS disks. ChatGPT gave instructions including a manual rescan and expanding of filesystem - 

Rescan Disk: echo 1 | sudo tee /sys/class/block/sda/device/rescan

Expand Filesystem: sudo resize2fs /dev/sda1

But actually, just needed to stop the vm in azure portal, resize in azure portal, then start in azure portal - since it is the OS disk and we're rebooting, the changes are automatically noted.

Microsoft's documentation for Windows VM also notes this, lower down in this page.

ode to github actions

Just a quick note of appreciation for Github Actions. I've moved most of my software work to directly editing on github and building with github actions, due to a variety of reasons, like

1. Relatively beefy build runners - much faster than the computers I have access to - completely free for public repositories, and generous allowances for free accounts' private repositories also.
2. I can start builds from the office and check the results at home etc - the advantages of having everything online.
3. Copilot's "Explain errors" makes it relatively easy to pinpoint and fix syntax errors and such.
4. I don't have to use up the limited hard disk space on local machines for relatively large SDKs like Android SDK, Android Studio, etc.
5. The issue tracker built into github makes it easy to keep track of bugs and fixes.
6. All the advantages of git source management.

For example, I'm trying out Android NDK for exploring OCVWarp or OpenSpace porting to Android / iOS, and all the samples finished building in just 15 minutes.

asked chatgpt about running x86-64 binaries with qemu on apple silicon

First, asked about running x86_64 Debian OS on Apple Silicon, since this medium article was paywalled - 
https://medium.com/@hathibel/debian-minimal-on-apple-silicon-qemu-setup-for-x86-64-3d6d2bc15e7d - 

ChatGPT's reply - 

Running x86-64 Debian with FluxBox on Apple Silicon (M1/M2/M3) using QEMU is a great way to emulate a lightweight Linux desktop environment on ARM-based Macs. Since Apple Silicon uses the ARM64 architecture, and you want to emulate x86_64, this setup requires full system emulation (not virtualization).

(snipping the detailed setup instructions for QEMU, since UTM is easier to use.)

and the reply ended with "QEMU x86 emulation is CPU intensive. Expect modest performance."

Then asked about how to run an OpenGL windows exe on apple silicon - it gave detailed pros and cons of the following options - 

1. Crossover (not free)
2. Wine + WineSkin or WineskinServer
3. UTM (QEMU-based VM with Windows x86_64)
4. Parallels ARM64 desktop (not free) with BoxedWine (a full x86 Wine stack on ARM)

Edit: Since this was for running OpenSpace, later got OpenSpace running on UTM after compiling it for ARM64 on Github Ubuntu ARM runners.

change submodule for a git repository

 When trying to build OpenSpace for ARM64, came across issues with webbrowser ext - CEF binary being downloaded was cef_binary_102.0.10+gf249b2e+chromium-102.0.5005.115_linux64.tar.bz2 while we need ...linuxarm64.tar.bz2 for ARM64

In this case, this file seems to be responsible - https://github.com/OpenSpace/OpenSpace/blob/master/modules/webbrowser/cmake/cef_support.cmake

which we can fork and modify. In general, for other submodules not present in the main repo, the procedure seems to be: 

How do I replace a git submodule with another repo? - Stack Overflow

If the location (URL) of the submodule has changed, then you can simply:

1. Modify the .gitmodules file in the repo root to use the new URL.
2. Delete the submodule folder in the repo rm -rf .git/modules/<submodule>.
3. Delete the submodule folder in the working directory rm -rf <submodule>.
4. Run git submodule sync. git submodule sync --recursive
5. Run git submodule update.

More complete info can be found elsewhere:

Changing remote repository for a git submodule

If repo history is different then you need to checkout new branch manually:

git submodule sync --recursive
cd <submodule_dir> 
git fetch
git checkout origin/master
git branch master -f
git checkout master

And apparently with Git 2.25 (Q1 2020), you can modify it.

git submodule set-url -- <path> <newurl>

git clone error and more - trying OpenSpace compile on Raspberry Pi

An initial trial - just to see what breaks - trying to git clone OpenSpace and build it on a Raspberry Pi 4.

cloning into 'OpenSpace'...

error: RPC failed; HTTP 408 curl 22 The requested URL returned error: 408

fatal: expected 'packfile'

Apparently, this was due to an apt upgrade happening in another terminal window. Tried again later, and the git clone succeeded.

Now the error is during the generation of cmake files, regarding not finding gcc-13 - compiling gcc may take 6 hours.

https://forums.raspberrypi.com/viewtopic.php?t=362502

some post says don't cross compile.

https://gcc.gnu.org/install/
make bootstrap-lean to use less disk space.

Maybe I'll first try on a github runner to look out for ARM errors - 

https://github.blog/news-insights/product-news/arm64-on-github-actions-powering-faster-more-efficient-build-systems/

"We expect to begin offering Arm runners for open source projects by the end of the year. "

https://docs.github.com/en/actions/using-github-hosted-runners/using-github-hosted-runners/about-github-hosted-runners#standard-github-hosted-runners-for-public-repositories

"The arm64 Linux runner is in public preview and subject to change."

libcef seems to be available for arm64, but some bugs for RPi

https://github.com/chromiumembedded/cef/issues/3803

Edit - arm64 build fails due to wrong CEF binary - will need to fork the project, make modifications ... 

prerequisites for running OpenSpace on Raspberry Pi

Initially, when I powered up the Pi, it showed a low-voltage warning on the Desktop (which I was accessing via RealVNC.) Disconnecting the powered USB hub, booting up with a 60W mobile charger - still the same warning. Then tried switching the USB-C cable to the charger's thicker cable as per
https://forums.raspberrypi.com/viewtopic.php?t=380368. That worked, no further warnings.

Check if mesa (software opengl rendering) is already the latest,

https://en.linuxadictos.com/table-23-3-arrives-with-official-support-for-rpi-5-experimental-support-for-nvk-and-more.html

On earlier pis, it used to be Fake KMS (KMS = Kernel Module Setting.)

https://forums.raspberrypi.com/viewtopic.php?t=255478

Comparison of Raspberry pi 5 with and without fan

https://www.digitec.ch/en/page/raspberry-pi-5--is-the-active-cooler-or-the-housing-with-fan-worth-it-31545

and lots of info in the comments of

https://www.raspberrypi.com/news/heating-and-cooling-raspberry-pi-5/

including the chart,

https://www.raspberrypi.com/app/uploads/2023/10/Screenshot-2023-10-04-at-23.15.30.png

About OpenGL compatibility -   

The VideoCore VII is capable of OpenGL ES 3.1 and Vulkan 1.2 according to

https://www.phoronix.com/review/raspberry-pi-5-graphics

and according to

https://docs.openspaceproject.com/releases-v0.20/contribute/development/compiling/index.html#hardware-requirements

OpenGL 3.3 is required.

So, we might need to use mesa software rendering,

https://raspberrypi.stackexchange.com/questions/75071/running-modern-opengl-on-raspberry-pi

OpenGL 3.3 is "mostly interoperable" with ES 2.0 - 

https://stackoverflow.com/questions/4519264/opengl-es-versus-opengl/11172984#11172984

Just in case this fake KMS is required on pi5

https://raspberrypi.stackexchange.com/questions/75071/running-modern-opengl-on-raspberry-pi

or just use qemu on pi?

https://raspberrypi.stackexchange.com/questions/4296/can-i-emulate-x86-cpu-to-run-teamspeak-3-server
https://marko97it.github.io/rpi5-qemu-win11/userguide/

(TPM mentioned above, is Trusted Platform Module.)

"AMD64 QEMU is currently way too broken to run a stable chroot"

in the comments of 

https://thepi.io/how-to-run-x86-programs-on-the-raspberry-pi/

and

https://github.com/ptitSeb/box86

is also 32 bit,

from https://raspberrypi.stackexchange.com/questions/108360/how-can-we-run-amd64-architecture-on-a-raspberry-pi-4

https://www.novaspirit.com/2019/04/15/run-x86-arm/

But "forget trying to run windows on it"

from

https://forums.raspberrypi.com/viewtopic.php?t=242211

Another possibility may be to cross compile.

https://earthly.dev/blog/cross-compiling-raspberry-pi/

Just try box64 first?

https://github.com/orgs/AppImage/discussions/1294

box64 with prebuilt binaries,

box64/docs/COMPILE.md at main · ptitSeb/box64

Error:

Cannot mount AppImage, please check your FUSE setup : r/debian

apt install fuse led to

The following packages will be removed:

fuse3 gvfs-fuse ntfs-3g xdg-desktop-portal xdg-desktop-portal-gtk xdg-desktop-portal-wlr

The following NEW packages will be installed:

  fuse

0 upgraded, 1 newly installed, 6 to remove and 4 not upgraded.

But even with that, the same fuse error for the x86-64 appimage running on box64. So, put back fuse3, ntfs-3g, and others. The warnings / errors seen are:

[BOX64] Binary search path: ./:bin/:/usr/local/sbin/:/usr/local/bin/:/usr/sbin/:/usr/bin/:/sbin/:/bin/:/usr/local/games/:/usr/games/

[BOX64] Looking for /media/user/SSD256GB01/rpiOpenSpace/OpenSpace-0.20.1-1-x86_64.AppImage

[BOX64] Rename process to "OpenSpace-0.20.1-1-x86_64.AppImage"

[BOX64] Warning, CALL to 0x0 at 0x401efd (0x401efc)

This doesn't look like a squashfs image.

[BOX64] Warning: Unsupported Syscall 0x54h (84)

Cannot mount AppImage, please check your FUSE setup.

You might still be able to extract the contents of this AppImage 

if you run it with the --appimage-extract option. 

See https://github.com/AppImage/AppImageKit/wiki/FUSE 

for more information

permissions needed to rename themes and plugins wordpress folders

 One of our wordpress websites was not entering recovery mode. 

... email from Wordpress regarding a fatal error while doing a setting in the menu using Astra theme. We had encountered such an error earlier also but could recover the site through the recovery link. However today on clicking on the recovery link it says recovery not initialized. ...

So, we had to disable plugins in order to be able to access the site. To follow the SSH/SFTP method described in this page - https://kinsta.com/knowledgebase/disable-wordpress-plugins/

But ... files could be opened but cannot rename since it says permission denied

So, just adding the ssh user to the www-data group was not enough - 

sudo adduser  thewordpresswebsiteadminuser www-data

also had to chmod the parent directory to 775 - was 755 earlier. 

cd theparentdirectory 
chmod -R 775 *

Then renaming worked.

Fixed by rebooting - VM on AWS

One of our VMs on AWS seemed to have some issue - it was not reachable by https or ssh. Apparently the network was down though the machine was running. Logged on to AWS portal, shut it down, and started it again, now it is working.