VMware ESXi Scratch Space

If you installed VMware ESXi on a USB stick like I did, the “scratch space” (used for storing logs and debug information) is stored on a RAM disk.  This takes up 512MB of memory that could otherwise be provisioned to virtual machines.  In addition, it does not persist across reboots, which explains why I was never able to find any logs after a crash. Also I was seeing random “No space left on device” errors when I was trying to run the munin monitoring script for ESXi.

The solution to this is to simply create a folder on a disk, and configure ESXi to use it.

  1. Login to the console or SSH to the host.
  2. Go into one of your datastores in /vmfs/volumes/
  3. Create a directory for the scratch space.
  4. Login to the vSphere Client.
  5. In the Host device, go to the Configuration tab, then find the Software category on the left menu and click Advanced Settings
  6. In the Configuration parameters window, find ScratchConfig on the left.
  7. For the “ScratchConfig.ConfiguredScratchLocation” box, enter the path to the folder you created in step 3.
    ESXi Advanced Settings Window
  8. Reboot the host.

It’s as simple as that!


Wi-Fi everywhere!

Over the past year, more and more ShawOpen Wi-Fi hotspots have been popping up everywhere around Metro Vancouver.

This is incredibly useful for Shaw customers (like me) because it’s so easy to find reliable Wi-Fi access anywhere we go.  If you’re a Shaw internet customer, you get to save several devices so that they can automatically connect to the network without having to login through the portal.

Telus is starting to form their own network as well, under the names #TELUS and #TELUSDirect.  The one advantage they have is that for Telus customers, #TELUSDirect is a secured Wi-Fi network, whereas ShawOpen is an open unsecured network.

I’m hoping that Shaw will consider providing a secure network for customers, but until then we’ll have to use our own VPN services to secure the Wi-Fi connection.

“Error: Boot loader didn’t return any data” when booting up Xen guest

Error: Boot loader didn't return any data

I have come across this error two or three times before, and each time I spend hours trying to figure out how to get my virtual machine to boot.  This blog post is just to document a fix so that I can refer back to it, and hopefully it will help people out if they’re experiencing the issue as well.

Continue reading ““Error: Boot loader didn’t return any data” when booting up Xen guest”

A week with the Google Glass

I had the opportunity to borrow the Google Glass from my workplace last week.

Google Glass is a wearable miniature computer mounted on a frame you wear like glasses. It has a small display that you can see through on the right eye.  Glass is still in the development process and these units aren’t the final product, so some of the issues may be solved by the time the final product ships.

First impressions

The Google Glass I had borrowed was one without prescription lenses.  Since I need to wear my own glasses, it was hard for me to get the Google Glass to fit on top of my glasses in a way where I could see the full screen. The left edge was cut off so my experience with it was affected.

The screen is also quite small, so there’s not a lot of things to see on the screen.  The main menus are just a scrollable list of words.  The two ways to interact with the Glass are by voice control, and a touch pad mounted on the right side of the frame.


Vancouver City Hall, taken from Google Glass
Vancouver City Hall, taken from Google Glass

I walked around with the Google Glass for a bit.  Took some photos and videos just to give it a try.  I didn’t have that many apps on the Glass so there wasn’t really much I could do (also one should probably be concentrated on walking in any case…).

More photos and videos taken from my walk with the Glass can be found on my Google Plus album.

In the car

I wrote an email to ICBC to get the official word on the rules about wearing Google Glass while driving, and as you may have guessed, it’s prohibited. Here’s a copy of the email I got back.

Based on information from Road Safety BC, we can inform you that the use of Google Glass while driving in BC is prohibited.

There are several sections of the Motor Vehicle Act that apply:

  • The most directly applicable section is Section 214.2 that lays out “Prohibition against use of electronic device while driving”. The “Use of Electronic Devices While Driving Regulation” prescribes “television” as an electronic device subject to the prohibition. Mobile operating systems and devices with wireless telephony, e.g. Google glass, smart watch, etc., are considered to be a variant of a “television” for purposes of the Act. They are considered as such because they fit within definitions of a television, for example, according to the Oxford English dictionary, Television is a system for converting visual images (with sound) into electrical signals, transmitting them by radio or other means, and displaying them electronically on a screen.
  • Section 144 of the Motor Vehicle Act lays out the prohibition against “careless driving” which could apply if using Google Glass while driving.
  • Sections 181 and 183 of the Motor Vehicle Act also require that drivers and cyclists exercise due care and attention when driving, so failing to do so due to distraction from using Google Glass is another way a person could violate of the rules.

So due to this I wasn’t able to try out the GPS navigation.


It’s pretty cool wearing the Google Glass. It feels like something from a sci-fi movie. But on the practical side of things there doesn’t seem to be that much useful stuff that can be done with the Glass right now as there are only a limited number of apps.  But I’m sure as time passes there will be more and more interesting apps that will make Glass a lot more useful.

More Detailed Wi-Fi Info on Mac OS X

Wi-Fi Detail Menu
Option-clicking on the Wi-Fi icon in the menu bar brings up additional information about the Wi-Fi network to which you are connected.

The option button can be used to reveal hidden options and information in various places around Mac OS.  One example of this is if you option-click the Wi-Fi icon in the menu bar, you will be presented with additional information about the network you are currently connected to, including the type of the Wi-Fi you’re using, the base station’s MAC address, the frequency channel you’re on, and the strength of the connection, among other details.  In addition, there is an additional option to open Wireless Diagnostics which might be able to help you with Wi-Fi issues (however, in my experience it doesn’t really give useful information).

Network Utility

Network Utility on the Info tab
Info tab in Network Utility

An additional tool to help debug network connections is a neat little utility called “Network Utility” that comes bundled with Mac OS X.  You can find it in the Utilities subfolder in the Applications folder, or just use Spotlight to find it.

This utility provides a friendly interface for many tools that are commonly used on the command line for network debugging, such as ping, nslookup, traceroute, whois, and finger. An interesting tool though is the last tab: Port Scan.  Yes, Mac OS comes with a port scanner bundled with it.  Obviously one would hope that the port scanner be used for diagnostic purposes and not malicious purposes.