Category: Linux

Linux

Register Red Hat 7 using Subscription Manager via Proxy

Mar 9, 2016 by Grzegorz Juszczak 0 Comments , , , , , ,

Register Red Hat 7 using Subscription Manager via Proxy
Once our Red Hat 7 system is installed, it should be registered at RHN using Subscription Manager in order to be able to get newest updates. If the server is placed in network behind firewall and outgoing traffic is blocked by firewall, the only reliable way of keeping our Red Hat 7 up-to-date is through proxy (if any exists).
Below we will show you in 2 simple steps, how to configure HTTP Proxy for Red Hat Subscription Manager and register Red Hat 7 with RHN in command line using HTTP Proxy:
Read More

Linux

nethogs – Display Network Utilization per Process

Mar 5, 2016 by Grzegorz Juszczak 0 Comments , , , , ,

ethernet_card
Have you ever wondered how to check network utilization by PID in Linux? Now it’s easy with nethogs application, which unlike other network utilization monitoring applications (nload, iftop) works like Linux top command, but displays network utilization per PID along with the network device used.

nethogs
Read More

Linux, Storage

GlusterFS Storage Setup on Two CentOS 7 Servers and Client

Jan 25, 2016 by Grzegorz Juszczak 5 Comments , , , , ,

glusterfs_logo
GlusterFS is a simple and easy to configure scalable network attached storage. GlusterFS is a distributed storage consisting of nodes (servers including storage bricks), which export their own local file system as a volume. Volumes can be mounted on client servers as a network storage using NFS and Gluster Fuse. GlusterFS provides failover, redundancy and anti split-brain mechanisms that act as a High Availability system, that’s why in many aspects it is similar to the well known clustering software like Veritas Cluster Suite.

In this tutorial we will install GlusterFS on two CentOS 7 based nodes. We will use KVM Virtual Machines to make things easier and faster, but our main intention is to show you how to install GlusterFS on physical hardware.
Read More

Linux

Upgrade from Fedora 21 to Fedora 22 using DNF

Jan 3, 2016 by Grzegorz Juszczak 0 Comments , , ,

fedora_logo
Starting from Fedora release 21 (Twenty One), Fedora can be upgraded using DNF system upgrade, which is recommended upgrade method for Fedora 21 and later releases. DNF is a kind of successor for FedUp (FEDora UPgrader), which is now obsolete, not supported any more by Fedora Project and should not be used in any circumstances.

In this article we will upgrade Fedora release 21 (Twenty One) to Fedora release 22 (Twenty Two) in five simple steps, using DNF system upgrade method.
Read More

Linux, Virtualization

How to Install Docker on Fedora 23

Jan 3, 2016 by Grzegorz Juszczak 0 Comments , ,

docker_logo
Docker is a software which automates the deployment of applications inside Linux containers, by providing an additional layer of abstraction. This guarantees that it will always run the same, regardless of the environment it is running in. Docker uses the resource isolation features of the Linux kernel such as cgroups and kernel namespaces to allow independent containers to run within a single Linux instance, avoiding the overhead of starting and maintaining virtual machines.

In this tutorial we will setup and launch Docker software on Fedora 23 (64-bit) release.

Prerequisites for Docker installation on Fedora release:
Fedora version: Fedora 22 (64-bit) or higher
kernel version: 3.10 or higher
Read More

Bash, Linux

ifdata – network interface information tool – ifconfig alternative

Dec 28, 2015 by Grzegorz Juszczak 0 Comments , , , ,

linux-terminal
ifdata is a quick, lightweight and simple tool to display network interface information in Linux, which can be used as an alternative for ip addr show or ifconfig.

Sometimes I want to quickly find out, if the particular network interface exists in the system or I want to display it’s IP address or MTU value only. If I used ifconfig for this case, I would have to parse the output using grep or other tools. ifdata resolves this problem in more sophisticated manner – it utilizes parameters to better control the output we want to obtain. This is another reason why ifdata is more friendly for use in BASH scripting.
Read More