linux server

Symlinks vs Hardlinks and how to create them

In a previous article I covered a little bit about Symlinks and Hardlinks but I never really explained what they are or how to create them. Today I am going to cover how to create both Symlinks and Hardlinks and what the difference is between the two. What are Symlinks and Hardlinks Hard Links In Linux when you perform an listing in a directory the listing is actually is a list of references that map to an inode.

Changing the default nice value for a user or group

Recently I coveredhow to increase and decrease the CPU priority of processes using nice and renice. Today I am going to cover how to change the default niceness value for a user or group. Why change the default CPU priority value? Before explaining how to change the default niceness value, let's cover why this could be useful. Scenario #1 You have a system that has thousands of users that log in via SSH and could potentially run CPU intensive tasks.

Understanding a little more about /etc/profile and /etc/bashrc

Recently I was working on an issue where an application was not retaining the umask setting set in the root users profile or /etc/profile. After looking into the issue a bit it seemed that the application in question only applied the umask setting that was set in /etc/bashrc and would not even accept the values being the applications own start scripts. After doing a bit of researched I learned a little bit more about what exactly these files do, the differences between them and when they are executed.

When it's Ok and Not Ok to use rc.local

On System V based OS's the /etc/rc.local file is executed by the init process at the end of the systems boot process. The fact that the rc.local file is executed during the boot process makes it an easy target for misuse by lazy Sysadmins. Since I started my Unix experience on FreeBSD which relies primarily on the /etc/rc.* configuration files, I've seen and shamefully contributed to my fair share of misuse in the rc.