This new article is about KVM and disk I/O performance based on this other article. It is for a smaller shop, not an enterprise with SAN storage.
I implemented one of the suggestions on my Windows7 Media Center virtual machine and saw about a 100% disk I/O throughput improvement even after already using virtio drivers. Going from 20MB/s to 40MB/s is pretty easy. Keep reading for the details.
Where is Curiosity?
I attended a local Ruby Meetup last week where they showed how to get all the dependencies for a smart RoR setup on Ubuntu. I’ve only tested it on 12.04 myself, but something similar should work for 10.04. I have doubts whether installing on 8.04 is this easy for the current versions of RVM, Ruby and Rails.
The installation instructions came from a gist from Cajun_Code. Following those instructions makes this process fairly straight forward. We’ll install RVM, Ruby v1.9.3, Rails, SQLite3, nginx and thin to get started.
There are lots and lots of IDEs out there. An IDE or Integrated Development Environment has been around for 30+ yrs. Many programmers my age remember Borland’s Turbo C IDE or Turbo Pascal. These had an editor, compiler and debugger built into 1 tool. They were small and fast AND very capable. Along the way, IDEs became more complicated and difficult to learn. They added connections to version control systems like
A modern IDE like Eclipse or Visual Studio needs a college level class just to understand how to use it. With all the added complexity, we’ve lost something. Issues with the IDE prevent programmers from coding all the time. I know this first hand – by trying to get Eclipse setup to work for shared Android development with a friend running it on MS-Windows. It was too complex. When I was a development lead, my guys were always having slightly different IDE configurations that caused issues for the other members of the team. This problem is common in team environments.
There are lots of options for lighter IDEs, geany is one. Geany isn’t exactly lite at 139M of RAM, but compared to most other IDEs, it is a feather. There’s a joke about Eclipse needing a Core i7 and 32GB of RAM to run well. I suspect even THAT will not help.
Geany is based on Scintilla like a few other very popular editors.
Every few months, I decide to install a newer version of Oracle’s VirtualBox on my laptop. Usually, this is really easy and everything goes well. Whenever I load up a new clientOS, I have to remember all the dependencies required to get the guest additions to compile and link. I always forget something or end up doing it a less-than-perfect way.
When I got up this morning, I noticed that Zimbra 7.2.0 was eating 100% of the available CPU on a KVM server. Some quick searches point to a Java leap-second bug AND a fix.
\# /etc/init.d/ntp stop
\# date `date +"%m%d%H%M%C%y.%S"`
\# echo “/etc/init.d/ntp start” | at now + 12 hours
It was amazing to see the CPU use drop immediately when the date command was run. Didn’t even need to restart any of the Zimbra processes. Amazing.
Life with Zimbra is good again. I’m just glad I was looking at the performance. If I hadn’t just done a Zimbra upgrade, I would never have bothered.
I’ve had dual monitors for years … many years.
I’ve had a KVM switch for longer. This lets us switch the main monitor, keyboard and mouse connections between 4 different physical PCs. KVM – Keyboard, Video, Mouse. Actually, you can chain multiple KVMs together and basically support over 30 different physical machines.
I’m not saying AV is completely useless, just that users should behave as though it is.
Best statement I’ve seen about AV in years. If you don’t want to be infected with a computer virus, run an AV tool (if on Windows), but act like you aren’t running an AV tool when you use the PC.
- The AV advertisers claim 80-90% protection.
- Security experts believe the truth is closer to 50% blocks.
I know which I believe and it isn’t the advertisers.
Act like your antivirus doesn’t work when browsing the internet. That sums up internet safety.
I don’t know that email firewall is the right term for the ScrollOut F1 toolset, but that’s what the tool claims. It is definitely good at blocking spam. Most people would call this an inbound email gateway.
Setting it up was pretty easy on a stock Ubuntu 12.04 JeOS virtual machine following the instructions over at HowToForge . Understanding the settings was a little harder. A few minor issues were also solved.
The last few weeks, we’ve been using Ubuntu 12.04 Server for internal testing as a VM host running KVM. The VMs have been a mix of 12.04, 10.04. and 8.04 systems. It has been stable with zero issues on that front. Below are the other changes recently made that you may find interesting.