Electromagnetic Wave Theory

So I am taking a follow up class (graduate-level) on the undergraduate-level Electromagnetic Fields and Waves course. It has been quite some time since I have looked at material like this in considerable depth and I have found that I need to re-introduce myself to many concepts.

Anyways, during my search I came across this handy resource. It has helped me understand several concepts I was having difficulties understanding, and with the examples they give, I can also re-learn good methods of approaching the problems at hand.

Creating/Adding an NFS Share

A couple days ago I had to create an NFS share at work. I never had to create one before but I found it to be quite painless. Here's how I did it in Sabayon Linux:

1. Start the nfs daemon if it is not already launched:

#/etc/init.d/nfs start

2. Edit the /etc/exports file (create it if needed) to include the share you wish to allow access to using the following syntax:

[full_path_to_share] [client_ip] ([privalages])

Example:

/home/aether/share 192.168.64.100 (rw)

3. Update the exports by running:

#exportfs -rv

Note: you may see some output warnings, but it will most likely still work.

4. You should now be able to mount the nfs share on the client

Bootloader Emulation

Modifying settings on a boot loader can be somewhat annoying; especially if you are inexperienced at it since you are prone to breaking the bootloader. When a bootloader is broken, often times you are forced to resort to throwing in a LiveCD/DVD and chrooting your filesystem and re-installing a fresh untampered bootloader. This is a time consuming and very annoying process. So...why not run an emulator of your current configuration so that in the event that the bootloader is broken, you know about it before you have to reboot. This allows the user to repair the bootloader in his filesystem rather than chrooting and all that mess that follows.

How do you emulate a bootloader you ask?
Simply download and install "qemu". For sabayon users just:

#equo install qemu

Then when the package is properly installed, run this:

#sync ; echo 3 > /proc/sys/vm/drop_caches ; qemu -hda /dev/sda

This assumes the bootloader is on the MBR. Adjust the command accordingly.

Not too shabby!