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{ Category Archives } Ubuntu

ZFS Administration, Part I- VDEVs

So, I've blogged a few times randomly about getting ZFS on GNU/Linux, and it's been a hit. I've had plenty of requests for blogging more. So, this will be the first in a long series of posts about how you can administer your ZFS filesystems and pools. You should start first by reading how to […]

How A ZIL Improves Disk Latencies

I just setup an SSD ZFS Intent Log, and the performance improvements have been massive. So much so, I need to blog about it. But first, I need to give you some background. I'm running a 2-node KVM hypervisor cluster replicating the VM images over GlusterFS (eventually over RDMA on a DDR InfiniBand link). One […]

How Much Swap?

I've been in the UNIX and GNU/Linux world since 1999. Back then, hard drives were barely passing double digits in GB, and RAM was PC100 speed at roughly 128 MB max. In fact, it wasn't uncommon for most systems to have 32 MB of RAM with an 8 GB hard drive. And we ran GNOME, […]

Haveged Continued

I noticed that on my machine, my entropy was staying high, then falling off. Then, at what appeared to be some arbitrary point, it would fill back up, in a very periodic manner. This is, of course, after running haveged in the background. Curious, I started looking into it. It took a while to find. […]

A Messaging Hub

I figured I would throw up a quick post about what I'm doing with my IRC client, and how it's turned into the de-facto messaging hub for just about everything in my online life. If it could handle SMTP/IMAP and RSS, it would be a done deal. My main client is WeeChat. It connects to […]

Libvirt, Tyan Motherboards, and UUID

I recently built two servers that I plan on using for a sandbox with various technologies (Infiniband, ZFS, RDMA, GlusterFS, Btrfs, Ceph, LXC, KVM, etc, etc, etc). So, getting everything installed and running, I ran into a rather interesting bug. I installed KVM and libvirt, and started rolling out some virtual machines. I wanted to […]

Aptitude Madness

I always use the "-R" or "--without-recommends", and this is why: root@yin:~# aptitude install virtinst The following NEW packages will be installed: acl{a} colord{a} consolekit{a} dconf-gsettings-backend{a} dconf-service{a} fontconfig{a} fontconfig-config{a} hicolor-icon-theme{a} libatk1.0-0{a} libatk1.0-data{a} libcairo-gobject2{a} libcairo2{a} libck-connector0{a} libcolord1{a} libcups2{a} libdatrie1{a} libdbus-glib-1-2{a} libdconf0{a} libdrm-intel1{a} libdrm-nouveau1a{a} libdrm-radeon1{a} libdrm2{a} libexif12{a} libfdt1{a} libfile-copy-recursive-perl{a} libfontconfig1{a} libgd2-xpm{a} libgdk-pixbuf2.0-0{a} libgdk-pixbuf2.0-common{a} libgl1-mesa-dri{a} libgl1-mesa-glx{a} libglapi-mesa{a} libgphoto2-2{a} […]

Install ZFS on Debian GNU/Linux

UPDATE (May 06, 2012): I apologize for mentioning it supports encryption. Pool version 28 is the latest source that the Free Software community has. Encryption was not added until pool version 30. So, encryption is not supported natively with the ZFS on Linux project. However, you can use LUKS containers underneath, or you can use […]

Mount Raw Images

Just recently, I needed to mount a KVM raw image file, because it was depending on a network mount that was no longer accessible, and any attempts to interact with the boot process failed. So, rather than booting off a live CD, or some other medium, I decided to mount the raw image file. After […]

Setup Network Interfaces in Debian

If you're not using NetworkManager or Wicd, or some other similar tool to automatically manage your network interfaces for you, this post is for you. In the Debian world, you have a single file that manages your network interfaces. It can manage VLANs, bonded interfaces, virtual interfaces and more. You can establish rules on what […]

Salt Packaged For Debian/Ubuntu

I created a Debian package for Salt, doing my best to adhere to the Debian Policy. You can find it at http://mentors.debian.net/package/salt. If you're not familiar with Salt, head over to http://saltstack.org and check it out. From the author's website: Salt is a powerful remote execution manager that can be used to administer servers in […]

How To Properly Create And Burn CD/DVD ISO Images From The Command Line

Too often, I see the recommendation on forums, IRC, and elsewhere across the internet to use improper tools for creating ISO images. For example, consider the following two commands, both of which are not the correct way to build a CD/DVD image: $ dd if=/dev/scd0 of=cdimage.iso # NO! Or worse yet: $ cat /dev/scd0 > […]

Avoid Using which(1)

This post comes from BashFAQ/081 on Greg's Wiki. He argues why you should not be using which(1) to determine if a command is in your $PATH at the end of the page. I'll put that argument at the front: The command which(1) (which is often a csh script, although sometimes a compiled binary) is not […]

Poll: Have You Ever Used A Floppy Disk?

This post is a quickie to see what the current generation is like these days. I'm an old fart (not as old as many reading this post), but I remember when 5 1/4" floppy drives were "standard", and 3 1/2" were the new fad. Then came Iomega Jazz drives, and the like. CDRW hit the […]

Why Unix Is Superior

Quick post, outlining what I think makes the Unix family of operating systems superior, including "unix-like" operating systems such as GNU/Linux, BSD, and others. Of course, the list isn't exhaustive- it's just something I threw together in 10 minutes. The motivation of the post was a discussion in ##unix on Freenode. The command line interface. […]