Category: Linux

CentOS 7 df command hangs

The df command is useful in reporting disk space usage.  However, recently encountered a system that would hang after issuing the df command.  A ctl c or ctl z would not escape this annoyance.  The issue was quickly resolved by reinstalling stystemd. After reinstalling systemd, the df command was reissued and was quite responsive. Source https://serverfault.com/questions/911811/centos-7-df-started-to-hangRead More »

The cd command in CentOS 7

I have been working in a CLI environment for many years, so the cd "change directory" command is nothing new to me; however, an accidental typo presented an unexpected result.  Instead of typing "cd .." which would transverse back one directory, a user typed only "cd" with the intention of pasting from the clipboard the rest of the path.  The...Read More »

VIM: Preserve File Date with Touch

I had a single file I needed to modify but didn't want to modify the date of the file.  It was a minor change to the file, so I wanted to maintain the file date for posterity.  In any case, I learned the vim does not provide this functionality, but touch would and quite easily.  With that said, I am...Read More »

Determine which processes are using swap in Linux

Some servers may have several applications, each running in their own allocated piece of RAM and SWAP.  It seems easy enough to use `top` to determine memory usage, but it wasn't so obvious (to me) as to how to determine swap usage.  A nifty little command called smem to the rescue. So what is smem?  It is a "Report memory...Read More »

ssh logins using keys

I have wanted to experiment and expand upon different ways of ssh'ing into one linux box from another using the ssh-keygen.  This article demonstrates several different methods that I have tested and used throughout the years. Actually what has happened, is that over time, scripting evolved and always seem to make tweaks along the way. Another variation. A more lengthy...Read More »

Spacewalk Certificate expiration warning [Resolved] 2018

I'm not going to go into detail as to what spacewalk is and what this message is all about, you are here for a reason.  You may have received an auto-generated email from Spacewalk to "inform you that your Spacewalk Certificate has expired on your [fqdn] server. After 4 day(s) the systems management services provided by your Spacewalk Server will...Read More »

How to add desktop icons on CentOS 7

For the most part, I prefer to work using the terminal on a minimal install of Linux; however, there are those occasional times where the GUI is necessary.  Recently faced with having to add a few desktop shortcuts to the Desktop posed a bit of a problem for me. Basically, wanted to achieve two things, a Desktop icon to launch...Read More »