Listener feedbacks from Mastodon, including commentary about the Julian calendar, Flatpak sandboxing problems, Flatpak usability problems, clarification on Bzip2 and LZMA and ZIP compression.

The overview of util-linux continues with mkswap, which designates a partition of a special hard drive or a special file as "swap" space. _NEVER run mkswap on a partition or file that contains data you care about._

$ sudo mkswap /dev/sdx1

The pivot_root command mounts a new location as your root whilst simultaneously unmounting the old one. You probably won't ever use pivot_root manually yourself. Its typical use case is during system startup, when an initrd is used to bootstrap an environment but then needs to be shunted away when the real root partition becomes available.

You can test pivot_root in a virtual machine, just as a proof of concept, as described in this episode, but if you have ever used chroot, then you have

The raw command talks directly to block devices, useful for fancy databases or other high-performance things that don't need a filesystem because they use their own optimized system for managing data. On some systems (like Slackware), you may need to do modprobe raw before using raw.

NEVER run raw against a block device with data (that you care about) on it. Here is a really simple proof of concept demo exercise:

# raw /dev/raw/raw1 /dev/sdx # echo "gnu world order" > /dev/sdx # dd if=/dev/raw/raw1 count=1 gnu world order [...]

The setserial command sets and reports serial ports on a Linux system. On Slackware, you can see the script that generates serial port definitions in /etc/rc.d/rc.serial, with its associated config file being /etc/serial.conf On a distro using systemd, there is a unit file that creates serial ports. Serial ports are usually accessible to the group dialout, so if you are having trouble talking to a device over a serial port, be sure to add yourself to the dialout group, and then log out and log back in. Permissions for devices that communicate over a serial port (like an Arduino) can be managed manually (chmod 660 /dev/ACM0, for instance) or you can script udev to set permissions upon connection.

Yes, there is a slight mixing error at the very start of the episode. Klaatu is currently on holiday and does not have the source files on hand.

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