In this post I’ll be discussing the fundamentals of the Logical Volume Manager in Linux, usually simply referred to as LVM. I’ve used LVM occasionally over the years, but for the most part I would just create a single big partition on my disk, toss XFS on it and call it a day. Recently that changed when I decided to replace my aging home media server with a new beast of a box that I wanted to do a lot more than simply serve up content. I knew I would need lots of storage, but didn’t necessarily know how I wanted to partition my disks ahead of time. I also wanted to move away from btrfs, which I never had a big problem with but I felt it would be better to use a more mainstream filesystem.
I’ve finally gotten sick of having a terrible wireless signal in my room, and I have a server in my office (hard wired via gigabit) so I figured I’d set it up as a wireless access point. There’s a lot of information in various places on how to set everything up, so I figured I’d try to wrangle everything in 1 spot.
Install the card.
I used a TP-Link WDN4800. Sadly I don’t have a list of all the compatible wireless cards, but it seems that having something based on the Atheros chipset is a good thing.
Amazon announced high I/O instances today. This is huge for anyone with a database larger than available memory, as it’s been a complete nightmare dealing with EBS up till now. Now your Cassandra, MongoDB, MySQL, or whatever your using should be able to perform well without requiring keeping your entire dataset in memory.
With each instance you get 2x1TB of disk. In this tutorial I’ll be setting it up as a RAID0 to get a single 2TB disk which should deliver excellent performance.
In this tutorial I’ll be guiding you through setting up a headless Ubuntu 11.10 box that you’ll manage using virt-manager, accessed via X11. My main machine is a Mac running OSX Lion. You’ll need the Ubuntu CD, and for the first part of the tutorial, physical access to the box with a keyboard and monitor.
**Install Ubuntu on your server. **
I installed Ubuntu Desktop so I could mess with virt-manager before I disconnected everything. You won’t be using much of the deskop feature so it might not matter to you. Just make sure you install openssh-server so you can connect later on.
Setting up a local cache is a smart idea if you’re going to be running a VM server, whether it be KVM, VirtualBox, or any other option really. I assume the same instructions will work with Debian, but I haven’t tried.
First up - install apt-cacher-ng.
apt-get install apt-cacher-ng
Add this to the bottom of your /etc/services:
apt-cacher 3142/tcp
apt-cacher 3142/udp
Edit /etc/default/apt-cacher and set AUTOSTART to 1.
Setting up a network bridge allows you to give a virtual machine it’s own IP address and make it accessible from the outside. A DHCP bridge is useful in a smaller network where static IPs aren’t assigned - like in a home or small office. You’ll want to do this if you’re setting up LXC or KVM.
This is what my /etc/network/interfaces config looks like.