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{ Category Archives } Ubuntu

Cryptographically Secure Pseudorandom Locally Administered Unicast MAC Addresses

Recently, Apple released the ability for iPhone 5c and newer hardware to create a spoofed software MAC address for 2.4 GHz and 5 GHz wireless access points. The MAC address is locally administered, and a unicast address. This has sparked a small discussion in various forums about how to generate valid locally administered unicast MAC […]

The Core Problem With Ubuntu Releases - Little QA

This post has a background bug that was introduced just over a week ago, ONE THE DAY BEFORE ITS RELEASE. The bug is being able to bypass the lock screen by just holding down your <Enter> key, letting Unity crash, then restarting without locking the desktop. That's a pretty big bug. What's interesting about this […]

ZFS Administration, Appendix D- The True Cost Of Deduplication

This post gets filed under the "budget and planning" part of systems administration. When planning out your ZFS storage pool, you will need to make decision about space efficiency, and the cost required to build out that architecture. We've heard over and over that ZFS block deduplication is expensive, and I've even mentioned it on […]

ZFS Administration, Appendix C- Why You Should Use ECC RAM

Introduction With the proliferation of ZFS into FreeBSD, Linux, FreeNAS, Illumos, and many other operating systems, and with the introduction of OpenZFS to unify all the projects under one collective whole, more and more people are beginning to tinker with ZFS in many different situations. Some install it on their main production servers, others install […]

Goodbye Ubuntu

In 1999, I discovered GNU/Linux. Before then, I was a Solaris fanboy. Solaris could do no wrong, and it even took until about 2003 before I finally made the plunge, and removed Solaris off my Sun Ultra 1 (complete with 21" CRT monitor), and put Debian GNU/Linux on it. It was either Debian, or Gentoo […]

Real Life NTP

I've been spending a good amount of my spare time recently configuring NTP, reading the documentation, setting up both a stratum 1 and stratum 2 NTP server, and in general, just playing around with NTP. This post is meant to be a set of notes of what I've learned in the process, and hopefully, it […]

Open Letter To All GNU/Linux and Unix Operating System Vendors

This is an open letter to all GNU/Linux and Unix operating system vendors. Please provide some sort of RSS or Atom feed for just new releases. Nothing else. No package updates. No "community" posts. No extra fluff. It shouldn't include news about being included in the Google Summer of Code. It shouldn't provide a list […]

Masquerade Computer Network Interfaces

I just recently acquired a Raspberry Pi at SAINTCON 2013. I already had one, and forgot how much fun these little computers can be. I also forgot what a PITA they can be if you don't have your house hard wired to your switch for Internet access, and have to go into the basement to […]

ZFS Administration, Appendix B- Using USB Drives

Introduction This comes from the "why didn't I think of this before?!" department. I have lying around my home and office a ton of USB 2.0 thumb drives. I have six 16GB drives and eight 8GB drives. So, 14 drives in total. I have two hypervisors in a GlusterFS storage cluster, and I just happen […]

ZFS Administration, Appendix A- Visualizing The ZFS Intent LOG (ZIL)

Background While taking a walk around the city with the rest of the system administration team at work today (we have our daily "admin walk"), a discussion came up about asynchronous writes and the contents of the ZFS Intent Log. Previously, as shown in the Table of Contents, I blogged about the ZIL in great […]

GlusterFS Linked List Topology

Lately, a few coworkers and myself decided to put our workstations into a GlusterFS cluster. We wanted to test distributed replication. Our workstations are already running ZFS on Linux, so we built two datasets on each of our workstations, and made them the bricks for GlusterFS. We created a nested "brick" directory to prevent GlusterFS […]

ZFS Administration, Part XVII- Best Practices and Caveats

Best Practices As with all recommendations, some of these guidelines carry a great amount of weight, while others might not. You may not even be able to follow them as rigidly as you would like. Regardless, you should be aware of them. I’ll try to provide a reason why for each. They’re listed in no […]

ZFS Administration, Part XVI- Getting and Setting Properties

Motivation Just as with Zpool properties, datasets also contain properties that can be changed. Because datasets are where you actually store your data, there are quite a bit more than with storage pools. Further, properties can be inherited from parent datasets. Again, not every property is tunable. Many are read-only. But, this again gives us […]

ZFS Administration, Part XV- iSCSI, NFS and Samba

I spent the previous week celebrating the Christmas holiday with family and friends, and as a result, took a break from blogging. However, other than the New Year, I'm finished with holidays for a while, and eager to get back to blogging, and finishing off this series. Only handful of posts left to go. So, […]

ZFS Administration, Part XIV- ZVOLS

What is a ZVOL? A ZVOL is a "ZFS volume" that has been exported to the system as a block device. So far, when dealing with the ZFS filesystem, other than creating our pool, we haven't dealt with block devices at all, even when mounting the datasets. It's almost like ZFS is behaving like a […]