This post is just a quick walk-through of some basic commands to help you find information about rpm packages. These commands will work for any rpm based distribution (Red Hat, Centos, Suse, Mageia). Debian based distributions like Ubuntu or Mint use dpkg instead of rpm and I’ll cover those in a different post. Query the rpm database You can query the rpm database to find a particular installed package using the -q option.
Linux is not a bulletproof operating system, no doubt flaws, vulnerabilities, and exploits exist at this very moment that are unidentified and unpatched. It’s also very likely that many Linux systems are running old unpatched kernels that are just waiting to be owned by some nefarious persons driven by who knows what motivations. Linux like Windows has a human flaw built into it, businesses don’t want downtime for updates, users want too many permissions, and sysadmins don’t want to risk breaking an application by running an OS update.
If you dig into the man pages for zypper , you will notice that zypper provides three distinct options for keeping your openSUSE system up-to-date; update (up) , patch , and dist-upgrade (dup) . If you aren’t familiar with zypper see my previous post managing packages with zypper for more information. In this post I will attempt to demonstrate the differences between each option and suggest when you may want to consider using each.
Satellite 6, Red Hat’s patch, configuration, and deployment management one stop shop solution is a powerful tool. It is also a formidable and complicated piece of software. One of the big hurdles that I have run into when incorporating Puppet into Satellite 6 is that many of our systems do not use a fqdn (fully qualified domain name) for their host names. Which means that when I register “superawesomewebserver01” with Satellite 6 I get a host record that reflects the short name.
In the previous two posts, we’ve looked at file permissions and access control lists. Today let’s take look at file attributes. Whereas, permissions and ACL’s deal with user and group access to a file, attributes are properties of a file that regulate how the operating system interacts with a given file. There are 15 file attributes: append only (a) , no atime updates (A) , compressed (c) , no copy on write (C) , no dump (d) , synchronous directory updates (D) , extent format (e) , immutable (i) , data journalling (j) , project hierarchy (P) , secure deletion (s) , synchronous updates (S) , no tail-merging (t) , top of directory hierarchy (T) , and undeletable (u) .
In the last post, we looked at basic file permissions. The ideas covered in that post are probably enough to get you through a large portion of the real world scenario’s that you will encounter. There are some special cases, however. One of them being access control lists (ACL) which I will discuss in this post. Access Control List - ACL As we saw in part 1 every file on a Linux system has an owner and a group associated with it, each of which has separate permissions.