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.
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.)
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!
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/
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 .
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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
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
-------------------------------------------------------------
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
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.
| 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 |
