Richard's Diary

Thursday, December 18, 2008

Runlevel Service Configuration Spent the past few days playing with sudo and runlevels. Some gotchas
  1. in opensuse, disabling the default all sudo, results in a bug in yast where it says the root password is invalid when it really is.
  2. don't mess with deleting default users and groups, unless you're willing to learn them all
    1. For instance, haldaemon, messagebus and avahi run processes needed by the system. But all of these had an ! in the shadow file, which means that the account is disabled or a * which means that no password will match so user can't login. So while it seemed like this accounts were not being used, they are.
    2. if one simply configures the firewall properly, then nothing can come in and nothing can go out
      http://www.linuxhomenetworking.com/wiki/index.php/Quick_HOWTO_:_Ch14_:_Linux_Firewalls_Using_iptables
  3. in opensuse and ubuntu (and most distros i suspect), you need to use the preinstalled boot init scripts.
    1. I tried creating my own using postgresql's contrib/start-scripts but it lacked the header so it didn't work even though i set up the symlinks correctly.
    2. Regardless of why that happened, package installers are prevalent, and since they do wipe out existing symlinks (supposedly) whenever a package is installed, it's best to just use the distro template init scripts and do "chkconfig --level 35 postgresql on"
    3. If you download an RPM from the distro repository, the package will have customized the template init script for you.
  4. Create guests that use NAT networking (as opposed to bridge networking) to take advantage of host connectivity to internet
Accomplishments
  1. begun my shell scripting training with sed, ways to run scripts
  2. use init 3 or init 5 to switch between those run levels
  3. list installed packages, install package and show package detail http://newbiedoc.sourceforge.net/tutorials/apt-get-intro/info.html.en

Distro notes
  1. CentOS seems to use really old packages.
  2. Didn't like Fedora GNOME - especially the software updating part. Couldn't tell if it was Fedora or GNOME that had these annoying messages saying this was waiting for that. But Fedora is Red Hat Linux and there is tons of documentation for that.
  3. Don't like KDE widgets
  4. Ubuntu takes some getting used to if you don't supply root with a password

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