Ubuntu

This is just a quick note on how to run Redis as a container using Podman on Ubuntu 22.04 (i.e. there will be no mention about SELinux.) Create a persistent volume for the Redis container I like storing all data/volume for containers under /srv/data. So I’ll create a sub-directory called redis-data under the same location. # mkdir -p /srv/data/redis-data Pull the Redis image # podman pull docker.io/redis Create and run the Redis container # podman run -d --name redis_server \ -v /srv/data/redis-data:/var/redis/data \ -p 6379:6379 redis Create systemd service for the Redis container I like creating a systemd service to enable/start the container. ...

This is just a quick note for me to display CPU temperature on one of my fanless device which runs Debian. Install the required package lm-sensors Run the sensors command. Here is a sample output: root@pve:~# sensors coretemp-isa-0000 Adapter: ISA adapter Package id 0: +45.0°C (high = +105.0°C, crit = +105.0°C) Core 0: +37.0°C (high = +105.0°C, crit = +105.0°C) Core 1: +37.0°C (high = +105.0°C, crit = +105.0°C) Core 2: +37.0°C (high = +105.0°C, crit = +105.0°C) Core 3: +37.0°C (high = +105.0°C, crit = +105.0°C) acpitz-acpi-0 Adapter: ACPI interface temp1: +27.8°C (crit = +119.0°C) Reference: ...

On RHEL 7/8, CentOS 7/8 and even Ubuntu (??), by default the journal log data is stored only in memory (/run/log/journal/ directory). There are 2 ways to retain the journal log messages. The first one is to set the variable Storage to persistent in the /etc/systemd/journald.conf. [Journal] Storage=persistent Then restart the systemd-journald service. Another solution is simpler and it looks like it’s the recommended way of achieving this. All we have to do is to create a directory, /var/log/journal (with correct ownership and permission), and journald will automatically store the log messages there. ...

Occasionally I see some of our Ubuntu machines having /boot partition filled up by the initrd files generated from old kernels which no longer were no longer installed on the machines. root@matht232:/boot# uname -a Linux matht232 5.3.0-40-generic #32~18.04.1-Ubuntu SMP Mon Feb 3 14:05:59 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux root@matht232:/boot# dpkg -l linux-image-\* | grep ^ii ii linux-image-5.3.0-40-generic 5.3.0-40.32~18.04.1 amd64 Signed kernel image generic ii linux-image-generic-hwe-18.04-edge 5.3.0.46.102 amd64 Generic Linux kernel image root@matht232:/boot# ls -1 /boot config-5.3.0-40-generic config-5.3.0-46-generic grub initrd.img-3.13.0-46-generic initrd.img-4.15.0-88-generic initrd.img-4.4.0-101-generic initrd.img-4.4.0-122-generic initrd.img-4.4.0-87-generic initrd.img-5.3.0-40-generic lost+found System.map-5.3.0-40-generic System.map-5.3.0-46-generic vmlinuz-5.3.0-40-generic vmlinuz-5.3.0-46-generic I tried to remove these initrd files manually, and they were generated again when a new kernel is installed. I haven’t figured how did this happened, until today! ...

When I plugged in an external drive to my laptop, the drive was displayed as a string consits random letters and numbers. Here is an example: ❯❯❯ df -Th | grep sdb /dev/sdb1 xfs 481M 26M 456M 6% /run/media/kenno/5428b182-c92e-466b-89d2-b5b31b80ba48 Though the drive worked perfectly fine, I think it’s ugly, and I wanted to properly give it a good name. Let’s call it externo. But how to do this? You may not believe it, I forgot how to do this. In fact, I couldn’t rememer when the last time I had to (re)label a file system. Fear not,Google can come to the rescue! ...