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GRE tunnels with systemd-networkd

·874 words·5 mins
Switching to systemd-networkd for managing your networking interfaces makes things quite a bit simpler over standard networking scripts or NetworkManager.

Understanding systemd’s predictable network device names

·1319 words·7 mins
I talked a bit about systemd’s network device name in my earlier post about systemd-networkd and bonding and I received some questions about how systemd rolls through the possible names of network devices to choose the final name.

Using ZoneMinder with a Logitech C270 webcam

·274 words·2 mins
For those of you in the market for a cheap webcam for videoconferencing or home surveillance, the Logitech C270 is hard to beat at about $20-25 USD.


Install sysstat on Fedora 21

·366 words·2 mins
One of the first tools I learned about after working with Red Hat was sysstat.

Helpful Linux I/O stack diagram

·78 words·1 min
During one of my regular trips to reddit, I stumbled upon an amazingly helpful Linux I/O stack diagram:


Learn octal file permissions easily with stat

·106 words·1 min
My SANS classmates were learning how to set and recognize file permissions on a Linux server and we realized it would be helpful to display the octal value of the permissions next to the normal rwx display.

Moving from OS X to Linux: Day One

·1418 words·7 mins
The thought of using Linux as a manager in a highly Windows- and Mac-centric corporate environment isn’t something to be taken lightly.

Installing the Xen hypervisor on Fedora 19

·596 words·3 mins
It’s been a little while since I last posted about installing Xen on Fedora, so I figured that Fedora 19’s beta release was as good a time as any to write a new post.

Presentation: Demystifying SELinux

·83 words·1 min
While rolling through my RSS feeds, I found a great presentation by David Quigley titled “Demystifying SELinux”.

Seriously, stop disabling SELinux

·147 words·1 min
After many discussions with fellow Linux users, I’ve come to realize that most seem to disable SELinux rather than understand why it’s denying access.


Compare commits between two git branches

·205 words·1 min
I found myself stuck in a particularly nasty situation a few weeks ago where I had two git branches with some commits that were mixed up.

New Fedora and EPEL package: httpry

·229 words·2 mins
A fellow Racker showed me httpry about five years ago and I’ve had in my toolbox as a handy way to watch HTTP traffic.

Kerberos for haters

·686 words·4 mins
I’ll be the first one to admit that Kerberos drives me a little insane.

Getting started with SELinux

·564 words·3 mins
I used to be one of those folks who would install Fedora, CentOS, Scientific Linux, or Red Hat and disable SELinux during the installation.

XenServer 6: Storage repository on software RAID

·760 words·4 mins
Although Citrix recommends against using software RAID with XenServer due to performance issues, I’ve had some pretty awful experiences with hardware RAID cards over the last few years.

SELinux and .forward files

·144 words·1 min
If you want to forward e-mail from root to another user, you can usually place a .


Dual-primary DRBD with OCFS2

·979 words·5 mins
As promised in one of my previous posts about dual-primary DRBD and OCFS2, I’ve compiled a step-by-step guide for Fedora.

Single boot Linux on an Intel Mac Mini

·576 words·3 mins
After reading the title of this post, you might wonder “Why would someone pay for a Mac Mini and then not use OS X with it?


Keep web servers in sync with DRBD and OCFS2

·535 words·3 mins
The guide to redundant cloud hosting that I wrote recently will need some adjustments as I’ve fallen hard for the performance and reliability of DRBD and OCFS2.

Switching from GlusterFS to DRBD and OCFS2

·174 words·1 min
As my uptime reports have shown, and as some of you have reported, my blog’s load time has increased steadily over the past few weeks.

Securing your ssh server

·748 words·4 mins
One of the most common questions that I see in my favorite IRC channel is: “How can I secure sshd on my server?

Parsing mdadm output with paste

·193 words·1 min
My curiosity is always piqued when I find new ways to manipulate command line output in simple ways.

Crash course in dsh

·371 words·2 mins
Thanks to a recommendation from [Michael][1] and [Florian][2], I’ve been using [dsh][3] with a lot of success for quite some time.




OpenSSL Tricks

·113 words·1 min
Create a strong CSR and private key

Installing package groups with up2date

·304 words·2 mins
A few days ago, I began to install a group of packages with up2date, and the person next to me was surprised that up2date even had this functionality.

Counting open files per user

·73 words·1 min
In the event that your system is running out of file descriptors, or you simply want to know what your users are doing, you can review their count of open files by running this command:

Yum equivalents of up2date arguments

·48 words·1 min
With RHEL 5 ditching up2date for yum, many Red Hat users might find themselves confused with the new command line flags.

RHEL limitations cheat sheet

·45 words·1 min
When you find yourself in a pinch, and you don’t know the limits of a certain Red Hat Enterprise Linux version, you can find this information in one place.

Low priority Plesk backups

·114 words·1 min
I hear a lot of complaints about Plesk’s backup routines and how they can bring a server to its knees.

Use a different IP for sending mail

·100 words·1 min
If you find yourself in a pinch and you need a temporary fix when your primary IP is blacklisted, use the following iptables rule:

Reset the Urchin admin password

·62 words·1 min
Should you find yourself in the situation where you’ve forgotten the Urchin admin password, don’t worry.

Upgrading FreeBSD remotely

·50 words·1 min
It can be best to upgrade FreeBSD in an offline state, but if you do it online, you can do it like this:

/bin/tar: Argument list too long

·52 words·1 min
If you find yourself stuck with over 30,000 files in a directory (text files in this example), packing them into a tar file can be tricky.

Basic SNMP Configuration

·55 words·1 min
If you want to get a really basic, wide-open for localhost setup for SNMP, just toss the following into /etc/snmp/snmpd.

Corrupt /dev/null

·107 words·1 min
If you find that /dev/null is no longer a block device, and it causes issues during init on Red Hat boxes, you will need to follow these steps to return things to normal: