All articles

  1. SSH Daemon on Alternate Ports

    There comes a time in every sysadmin's life where they need to run SSH on an alternate port. Should be as simple as adding multiple Port <number> directives to /etc/sshd/config and issuing a restart to the daemon.

    Except SELinux, as usual, finds a way to rain on the …

  2. Deduplication and You

    I was doing some backups and realized my photos, which I keep in Dropbox (sue me) were taking up about 50G. I knew there had to be a lot of duplicates but searching for them through 50G of files would be tedious. This seemed like a task that should be …

  3. Encryption with a Funky Partition Layout

    I recently ran into some trouble with the system while mucking around and decided to take the opportunity to restructure my partitioning layout and do a full OS reinstall; this time with full disk encryption (except /boot). Suffice it to say, the Fedora installer is fairly flexible, but not nearly …

  4. Weather Shell Function

    Here's the weather function I use when I'm too lazy to look out the window. The only configuration is a free forecast.io API key. The main selling point is that it geolocates so you don't have to remember where you are. Though this has drawbacks if you're running it …

  5. CIFS, fstab, and You

    Let's say you're a Linux admin in a Windows shop (ha) and you'd like to be able to access your company shares via a real operating system. Even more, you'd like these shares to be accessible immediately after boot.

    //<server>/path /path/to/mount  cifs credentials=/home/<username>/.smbcreds,uid …
  6. Leveraging LVM Caching

    I recently implemented LVM caching based largely on Richard WM Jones' post and thought I'd document my own experience here.

    I started with an SSD containing /, /home, and swap, two 2 TB HDDs (sdb, and sdc) and an additional SSD (sdd).

    [root@bender ~]# lsblk
    NAME            MAJ:MIN RM   SIZE RO …
  7. Enable SSD Trim Support with systemd

    # systemctl enable fstrim.timer
    Created symlink from /etc/systemd/system/multi-user.target.wants/fstrim.timer to /usr/lib/systemd/system/fstrim.timer.
    # systemctl start fstrim.timer
    # systemctl status fstrim.timer
     fstrim.timer - Discard unused blocks once a week
       Loaded: loaded (/usr/lib/systemd/system/fstrim.timer; enabled; vendor preset: disabled …
  8. Military Cheaters Sorted By Branch

    $ egrep '.mil$' ashley_madison_tlds.txt | sort | uniq -c | sort -nr | head -n10
    6873 us.army.mil
    1718 navy.mil
     845 usmc.mil
     206 mail.mil
     127 gimail.af.mil
      62 med.navy.mil
      57 us.af.mil
      55 usarmy.mil
      49 uscg.mil
      39 usarec.army.mil
    
  9. CentOS 7 FirewallD Initial Setup

    I fired up my first CentOS 7 instance and there are a lot of new things that I’ve been avoiding learning. Namely, FirewallD. According to the wiki page:

    firewalld provides a dynamically managed firewall with support for network/firewall zones to define the trust level of network connections or …