A block devices is usually a physical device that’s used for storing data, e.g. Hard drives and solid state drives. A partition is basically a way to organise a block device’s storage into smaller segments, that means creating partitions allows you to use a percentage of your block device’s storage space for a specific purpose and leave the rest available for other uses.
A storage device is a term used loosely to mean anything that’s used for storing data. Storage devices comes in various forms, but they most commonly in the form of a partition (e.g. /dev/sdb2), or an unpartitioned block device (e.g. /dev/sdc), or a logical volume (e.g. /dev/mapper/centos-home). Before you can […]
To start storing data on a block device (e.g. a partition, logical volume, or antire storage device) you first need to install a filesystem on the block device. After that you then need to mount the filesystem. Mounting a filesystem is simply the act of associating a directory (aka a […]
In linux there are lots of processes running, there are a number of commands available to find and view these processes.
One thing you may want to do is to find and stop a process. There are a few ways to do this, but they all involve sending a process a “signal”. A signal is an instruction that can be sent to a process. Processes aren’t allowed to ignore an incoming […]
Changing a process’s priority is a good way to make your machine run more efficiently. Changing process priorities is to do with increasing/decreasing how much CPU time a process can have while the machine is running. For example if you are setting up a machine to primarily run as a web server, then it is a good idea to elevate the web-server related processes so that they get more access to the CPU.
If you have forgotten what your CentOS/RHEL system’s root password is, then you need to reset your machine’s root password. Resetting the root password requires rebooting your CentOS 7 machine, and then edit the GRUB parameters during boot time.
A unit is a resource that systemd can manage. If you look inside the /usr/lib/systemd/system directory, you will find files with different extensions, e.g. .socket, .target, .mount, …etc.
jobs are processes that are triggered by you, when you run various commands in your current bash/putty terminal.
Journald is a service that systemd uses for capturing logs