Qcow2 is the default virtual disk storage format used by Qemu (qcow stands for qemu copy-on-write). This image format makes use of thin provisioning, so, after we initially set the maximum virtual size of a disk, space is actually allocated only when used, but not made available back to the host when freed.
Commands
Preserve file permissions and ownership with cp command
The cp command on a Linux system is one of the most basic commands that many users will utilize every day, whether they are new to Linux or a system administrator.
adduser vs useradd in Linux
All Linux systems have access to hundreds or thousands of different commands. Some of these commands serve similar purposes, though there is usually a particular tool that is more suited for certain jobs. Such is the case with the adduser and useradd commands on Linux.
Nohup command in Linux with Examples
The nohup command in Linux is used to tell a process to ignore any SIGHUP (hangup) signals that it receives. The SIGHUP signal is sent to a background job whenever the current terminal is closed. Thus, we can have a job in the background, close the terminal, and still see it running in the background.
Linux commands cheat sheet
The command line terminal in Linux is the operating system’s most powerful component. However, due to the sheer amount of commands available, it can be intimidating for newcomers. Even longtime users may forget a command every once in a while and that is why we have created this Linux cheat sheet commands guide.
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Using ps sort by memory
The ps command in Linux can tell us all sorts of information about the running processes on our system. The command also reports memory usage for each running process. In this tutorial, you’ll see how to list processes on Linux, sorted by their memory consumption.
kill vs killall – difference and command usage
This article will discuss a difference between kill vs killall commands. Killing processes on a Linux is an essential thing for admins and users to know. At some point, you’ll encounter an application or services that hangs and freezes, and you’ll need to kill the process to exit it.
mount command in Linux with examples
We can use the mount command in Linux to attach file systems and removable devices such as USB flash drives. The default file system for most Linux distributions is ext4. We can also dismount file systems with the unmount command.
dd command in Linux with examples
Linux considers anything stored on a file system as files, even block devices. This means commands such as the dd command in Linux can be very handy in many situations, as it can be used to convert and copy files in the terminal, backup disks, or wipe data. The dd command is just as fundamental as it is useful, as it’s ready to use even on the most basic installations of Linux distros.
du command in Linux with examples
On any operating system, the files on your hard disk take up a certain amount of space. In Linux specifically, you can view how much space that these files take up in the command line terminal by using the du command. The du command (the name is shortened from “disk usage”), as the name implies, will simply display, in its output, the amount of disk space being used by a specified file or directory.