What’s behind the Linux umask

By Sandra Henry-Stocker

The umask setting plays a big role in determining the permissions that are assigned to files that you create. But what’s behind this variable and how do the numbers relate to settings like rwxr-xr-x?

First, umask is a setting that directly controls the permissions assigned when you create files or directories. Create a new file using a text editor or simply with the touch command and its permissions will be derived from your umask setting. You can look at your umask setting simply by typing umask on the command line.

$ umask
0022

Where the umask setting comes from

The umask setting for all users is generally set up in a system-wide file like /etc/profile, /etc/bashrc or /etc/login.defs — a file that’s used every time someone logs into the system. The setting can be overidden in user-specific files like ~/.bashrc or ~/.profile since these files are read later in the login process. It can also be reset on a temporary basis at any time with the umask command.

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From: Network World

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What you need to know to manage Linux disks

By Sandra Henry-Stocker

How much do you need to know about disks to successfully manage a Linux system? What commands do what? How do you make good decisions about partitioning? What kind of troubleshooting tools are available? What kind of problems might you run into? This article covers a lot of territory – from looking into the basics of a Linux file systems to sampling some very useful commands.

Disk technology background

In the beginning days of Unix and later Linux, disks were physically large, but very small in terms of storage capacity. A 300 megabyte disk in the mid-90’s was the size of a shoebox. Today, you can get multi-terrabyte disks that are the size of a slice of toast.

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From: Network World

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Linux commands for managing, partitioning, troubleshooting

By Sandra Henry-Stocker

How much do you need to know about disks to successfully manage a Linux system? What commands do what? How do you make good decisions about partitioning? What kind of troubleshooting tools are available? What kind of problems might you run into? This article covers a lot of territory – from looking into the basics of a Linux file systems to sampling some very useful commands.

Disk technology

In the beginning days of Unix and later Linux, disks were physically large, but very small in terms of storage capacity. A 300 megabyte disk in the mid-90’s was the size of a shoebox. Today, you can get multi-terrabyte disks that are the size of a slice of toast.

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From: Network World

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Maneuvering around run levels on Linux

By Sandra Henry-Stocker

On Linux systems, run levels are operational levels that describe the state of the system with respect to what services are available. One run level is restrictive and only used for maintenance; network connections will not be operational, but admins can log in through a console connection. Others allow anyone to log in and work, but maybe with some differences in the available services. This post examines how run levels are configured and how you can change the run level interactively or modify what services are available.

The default run state on Linux systems — the one that will be used when the system starts up (unless instructed otherwise) — is usually configured in the /etc/inittab file which generally looks something like this:

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From: Network World

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Review: 5 top Linux distros for enterprise servers

By Susan Perschke

Linux distros are plentiful, and choosing the right server product can be a daunting task. Are you looking for a supported product, or can you go with a free version? Need Cloud support or virtualization? We’ll try to provide some answers.

Although many Linux distros can quite capably be configured to run as a server, for this review we focused solely on dedicated server products, named and supported as such.

+MORE ON NETWORK WORLD: What is Linux? A powerful component of modern data centers+

We tested Ubuntu LTS (long-term support) 16.04.02, Red Hat Enterprise Linux Enterprise Server 7.4, SUSE Linux Enterprise Server 12 SP2, Fedora Server 26 and Oracle Linux 73. All five products tested are designed and supported as server operating systems, and each product boasts a large user base. However, each of these products appeals to a different target audience, as noted in the narrative and summary chart.

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From: Network World

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