www.debuntu.org/device-partition-labeling

The part on labeling FAT filesystems is not quite right. It works, but there is a better way. First make sure you have the debian package “mtools” installed:

To see if there is a label already there:
sudo mlabel -i /dev/device -s ::

To write a new label:
sudo mlabel -i /dev/device ::newlabel

In the place of “/dev/device” you should use something like “/dev/sdd1″.

It turns out Lyceum was not dead. Huh.

Of course the Post Levels plugin still does not work, which is a huge bummer.

useful-netcat-tricks

Looking at the comments of that blog I saw another cool thing to do involving network transfer of files. It introduces a utility I didn’t know about before called lzop. It goes something like this:

On the sending computer…

dd if=/home/me/my_file | lzop | nc 192.168.0.1 9000


On the receiving computer…

nc -l -p 9000 | lzop -d |dd of=/someplace/my_file


So, the sending computer uses dd to pipe the file to lzop (which compresses it) then pipes it to netcat. The receiving computer gets the file via netcat, pipes it to “lzop -d” to decompress it, and finally dd gets it and writes it to disk. With lzop providing compression the transfer should go pretty quick. If the file compresses easily. Lzop is preferred in this case because it is supposed to much quicker than gzip, so it doesn’t get in the way while doing its thing.

A potential downside to sending huge files is that you have no progress meter. I suppose you can do a ls from time to time to judge when the file transfer will be done.

I have not tried any of this yet…

Apache JMeter may be used to test performance both on static and dynamic resources (files, Servlets, Perl scripts, Java Objects, Data Bases and Queries, FTP Servers and more). It can be used to simulate a heavy load on a server, network or object to test its strength or to analyze overall performance under different load types. You can use it to make a graphical analysis of performance or to test your server/script/object behavior under heavy concurrent load.

What was hard was finding authoritative documentation for VLANs on Debian. Maybe I was looking in the wrong places (google), I don’t know. It turns out it is a simple procedure. Finding the info and experimenting took all the effort.

First you install the “vlan” package so you will have the utilities needed to manipulate VLANs:

apt-get install vlan

Then you define your VLAN interfaces in /etc/network/interfaces like so:
auto vlan2
iface vlan2 inet static
vlan_raw_device eth0
address 192.168.22.20
netmask 255.255.255.0
network 192.168.22.0
broadcast 192.168.22.255
gateway 192.168.22.1


UPDATE:
Well that project crashed and burned. It turns out that I am limited by the switch. It is necessary to use port mirroring on the switch so that the monitoring server will get all the network traffic from the other servers. With the switch I have (HP 4104gl) you can only mirror ports that are on the same module as the monitoring port. The switch has four modules, with servers populating all four. So that restricts things quite a bit. Too much to make it worth it in fact.

At least I figured out that I don’t need to use VLANs for monitoring (it was a good learning experience though).

HP/Proliant Installer Compatibility Table

It lists what Debian works on what HP servers. This should save a lot tears and moaning.

Update: Holy crap, HP has a page for Debian compatibility too!

HP and Debian GNU/Linux

Blade servers are a go. Freaking cool.

This model works great with Etch, apparently:

installation-report: HP ProLiant DL145 G3

make-ssl-cert template output-certificate [--force-overwrite]

An example of a SSL template can be found here:

/usr/share/ssl-cert/ssleay.cnf

I got this from reading a blog entry here: SSL + Apache2.2 + VirtualHost + Debian with automatically HTTPS forwarding

Bash Shell Keyboard Shortcuts

The meat of the actual article after the jump…

* Ctrl + A - Go to the beginning of the line you are currently typing on

* Ctrl + E - Go to the end of the line you are currently typing on

* Ctrl + L - Clears the Screen, similar to the clear command

* Ctrl + U - Clears the line before the cursor position. If you are at the end of the line, clears the entire line.

* Ctrl + H - Same as backspace

* Ctrl + R - Let’s you search through previously used commands

* Ctrl + C - Kill whatever you are running

* Ctrl + D - Exit the current shell

* Ctrl + Z - Puts whatever you are running into a suspended background process. fg restores it.

* Ctrl + W - Delete the word before the cursor

* Ctrl + K - Clear the line after the cursor

* Ctrl + T - Swap the last two characters before the cursor

* Esc + T - Swap the last two words before the cursor

* Alt + F - Move cursor forward one word on the current line

* Alt + B - Move cursor backward one word on the current line

* Tab - Auto-complete files and folder names

* Ctrl + W - erase word before cursor

* Ctrl + Y - to paste it (as in delete and copy) all text in front of the cursor

* Esc + . (or Esc + Underscore) - Insert Last Argument

* Ctrl + b - Move back a character

* Ctrl + f - Move forward a character

* Ctrl + r - Search the history backwards

* Ctrl + xx - Move between EOL and current cursor position

* Ctrl + x @ - Show possible hostname completions

* Alt + < - Move to the first line in the history

* Alt + > - Move to the last line in the history

* Alt + ? - Show current completion list

* Alt + * - Insert all possible completions

* Alt + / - Attempt to complete filename

* Alt + . - Yank last argument to previous command

* Alt + c - Capitalize the word

* Alt + d - Delete word

* Alt + l - Make word lowercase

* Alt + n - Search the history forwards non-incremental

* Alt + p - Search the history backwards non-incremental

* Alt + r - Recall command

* Alt + t - Move words around

* Alt + u - Make word uppercase

* Alt + back-space - Delete backward from cursor

* Here “2T” means Press TAB twice

* $ 2T - All available commands(common)

* $ (string) 2T - All available commands starting with (string)

* $ /2T - Entire directory structure including Hidden one

* $ 2T - Only Sub Dirs inside including Hidden one

* $ *2T - Only Sub Dirs inside without Hidden one

* $ ~2T - All Present Users on system from “/etc/passwd”

* $ $2T - All Sys variables

* $ @2T - Entries from “/etc/hosts”

* $ =2T - Output like ls or dir