Long DNS Resolving time in Ubuntu 9.10

It all begins after the first update of a fresh ubuntu 9.10 install. Everytime I opened a browser and go any website, it takes 5-10 seconds for it to resolve the DNS. This applies to both Chrome and Firefox. I did tons of research on the internet. Lots of people concluded it is caused by the new DNS mechanism in Firefox 3.5. In this version, Firefox tend to use ipv6 to resolve DNS at first. Then after 3 failures, it will start to use ipv4. So people suggested to config firefox so that ipv6 is disabled. Also, some others suggested this is not enough, an update on the Grub to completely block ipv6 is necessary. I tried both, but neither of them solves the issue.

By "time dig www.google.ca", it still takes nearly 5 sec to "looking for host".

Then I read this:

http://www.unixmen.com/linux-tutorials/567-internet-connexion-is-very-slow-on-karmic-koala-solution-

By manually specifying DNS address (I got it from my router's config, do not use your router as the DNS server), the issue is solved.

100 Vim commands a programmer should know

From: http://www.catswhocode.com/blog/100-vim-commands-every-programmer-should-know

Search

/word	Search “word” from top to bottom
?word	Search “word” from bottom to top
/jo[ha]n	Search “john” or “joan”
/\<>	Search “the”, “theatre” or “then”
/the\>	Search “the” or “breathe”
/\<>	Search “the”
/\< ….\>	Search all words of 4 letters
/\/	Search “fred” but not “alfred” or “frederick”
/fred\|joe	Search “fred” or “joe”
/\<\d\d\d\d\>	Search exactly 4 digits
/^\n\{3}	Find 3 empty lines
:bufdo /searchstr/	Search in all open files

Replace

:%s/old/new/g	Replace all occurences of “old” by “new” in file
:%s/old/new/gw	Replace all occurences with confirmation
:2,35s/old/new/g	Replace all occurences between lines 2 and 35
:5,$s/old/new/g	Replace all occurences from line 5 to EOF
:%s/^/hello/g	Replace the begining of each line by “hello”
:%s/$/Harry/g	Replace the end of each line by “Harry”
:%s/onward/forward/gi	Replace “onward” by “forward” , case unsensitive
:%s/ *$//g	Delete all white spaces
:g/string/d	Delete all lines containing “string”
:v/string/d	Delete all lines containing which didn't contain “string”
:s/Bill/Steve/	Replace the first occurence of “Bill” by “Steve” in current line
:s/Bill/Steve/g	Replace “Bill” by “Steve” in current line
:%s/Bill/Steve/g	Replace “Bill” by “Steve” in all the file
:%s/\r//g	Delete DOS carriage returns (^M)
:%s/\r/\r/g	Transform DOS carriage returns in returns
:%s#<[^>]\+>##g	Delete HTML tags but keeps text
:%s/^\(.*\)\n\1$/\1/	Delete lines which appears twice
Ctrl+a	Increment number under the cursor
Ctrl+x	Decrement number under cursor
ggVGg?	Change text to Rot13

Case

Vu	Lowercase line
VU	Uppercase line
g~~	Invert case
vEU	Switch word to uppercase
vE~	Modify word case
ggguG	Set all text to lowercase
:set ignorecase	Ignore case in searches
:set smartcase	Ignore case in searches excepted if an uppercase letter is used
:%s/\<./\u&/g	Sets first letter of each word to uppercase
:%s/\<./\l&/g	Sets first letter of each word to lowercase
:%s/.*/\u&	Sets first letter of each line to uppercase
:%s/.*/\l&	Sets first letter of each line to lowercase

Read/Write files

:1,10 w outfile	Saves lines 1 to 10 in outfile
:1,10 w >> outfile	Appends lines 1 to 10 to outfile
:r infile	Insert the content of infile
:23r infile	Insert the content of infile under line 23

File explorer

:e .	Open integrated file explorer
:Sex	Split window and open integrated file explorer
:browse e	Graphical file explorer
:ls	List buffers
:cd ..	Move to parent directory
:args	List files
:args *.php	Open file list
:grep expression *.php	Returns a list of .php files contening expression
gf	Open file name under cursor

Interact with Unix

:!pwd	Execute the “pwd” unix command, then returns to Vi
!!pwd	Execute the “pwd” unix command and insert output in file
:sh	Temporary returns to Unix
$exit	Retourns to Vi

Alignment

:%!fmt	Align all lines
!}fmt	Align all lines at the current position
5!!fmt	Align the next 5 lines

Tabs

:tabnew	Creates a new tab
gt	Show next tab
:tabfirst	Show first tab
:tablast	Show last tab
:tabm n(position)	Rearrange tabs
:tabdo %s/foo/bar/g	Execute a command in all tabs
:tab ball	Puts all open files in tabs

Window spliting

:e filename	Edit filename in current window
:split filename	Split the window and open filename
ctrl-w up arrow	Puts cursor in top window
ctrl-w ctrl-w	Puts cursor in next window
ctrl-w_	Maximise current window
ctrl-w=	Gives the same size to all windows
10 ctrl-w+	Add 10 lines to current window
:vsplit file	Split window vertically
:sview file	Same as :split in readonly mode
:hide	Close current window
nly	Close all windows, excepted current
:b 2	Open #2 in this window

Auto-completion

Ctrl+n Ctrl+p (in insert mode)	Complete word
Ctrl+x Ctrl+l	Complete line
:set dictionary=dict	Define dict as a dictionnary
Ctrl+x Ctrl+k	Complete with dictionnary

Marks

mk	Marks current position as k
‘k	Moves cursor to mark k
d’k	Delete all until mark k

Abbreviations

:ab mail mail@provider.org

Define mail as abbreviation of mail@provider.org

Text indent

:set autoindent	Turn on auto-indent
:set smartindent	Turn on intelligent auto-indent
:set shiftwidth=4	Defines 4 spaces as indent size
ctrl-t, ctrl-d	Indent/un-indent in insert mode
>>	Indent
<<	Un-indent

Syntax highlighting

:syntax on	Turn on syntax highlighting
:syntax off	Turn off syntax highlighting
:set syntax=perl	Force syntax highlighting

add public key

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 247D1CFF

Hard Drive Access Time

Hard Drive Latency

Mechanical latencies, measured in milliseconds, include both seek time and rotational latency. "Seek Time" is measured defines the amount of time it takes a hard drive's read/write head to find the physical location of a piece of data on the disk. "Latency" is the average time for the sector being accessed to rotate into position under a head, after a completed seek. It is easily calculated from the spindle speed, being the time for half a rotation. A drive's "average access time" is the interval between the time a request for data is made by the system and the time the data is available from the drive. Access time includes the actual seek time, rotational latency, and command processing overhead time.

Collected From: http://www.pctechguide.com/31HardDisk_Performance.htm

Windows Performance Monitor

Launch the process you want to monitor
Launch Perfmon
Left-hand pane, expand Performance Logs and Alerts, select Counter Logs
Right-click in right-hand pane, select New Log Settings & give it a name
Click Add Counters
Select Performance object: Process
Make your select of counter(s) & instance(s) - your process should be listed as an instance

Hint: Even if I want information on a specific process, I tend to select All counters and All instances, then just filter when I come to review the information

Click Add, then Close
Set your sample interval to suit (default is 1 per 15 seconds)

Click OK (and again if you get prompted that the folder you specified for the log does not exist)

When you want to start monitoring the process, right-click on the counter log and select Start (and later repeat but select Stop when you are ready to stop logging).


When you come to review the data, launch Perfmon and right-click on the graph then select Properties
Go to the Source tab and select Log files, then click Add
Browse to your .BLG file and add it, then click Apply
Select the Data tab and click Add - now you should only see all the processes that were running when you logged the data - find the instance(s) and counter(s) that are interesting and click Add for each, then Close

Click OK and you should see the logged information about the counter(s) selected - the default Y-axis is 0-100 so should work perfectly for percentage counters (for others you can manually the scale of the counter to make it fit, or the scale of the graph itself).


Hint: If you have multiple counters visible, use CTRL-H to highlight the selected one

Install nvidia official drivers 180.22 on Ubuntu 8.10

The idea was inspired by the instructions on:

https://help.ubuntu.com/community/NvidiaManual

I followed exactly on the instruction says, but the error:

Failed to initialize the NVIDIA kernel module

keeps poping up. And gnome can only start with the resolution of 640*480. After googling around a little bit, I found the following posts:

http://www.nvnews.net/vbulletin/showthread.php?t=38398

To sum up, here is what you need to do:

First, go to System-> Administration -> Hardware Drivers, and disable any active resticted drivers. Ironically, I felt like this step should have already been included in the official instructions posted on ubuntu wiki. However, apparently you need to do this by your own. Then, run

sudo cp -a /dev/nvidia* /etc/udev/devices/

It is funny that this step should have done by the nvidia installation script, well, judging from my m$ experiences. But NO! You still need to googling around and find the answer to it. Well, I am not sure if it is included in the nvidia README.txt, but I got no time to read through the 600 line instruction manual. To summarize, I do not think Ubuntu is for lazy people like me. It is still not a linux for human, as they claimed. It's sad.

Ubuntu 8.10 Intrepid freezing from idle or after suspension

Affect: Any system that comes with a wireless n card.

Symptom: Freezing from idle or after suspension, LED of capslock frequently flashing.

Fix: sudo apt-get install linux -backports-modules-intrepid

Slow in opening media file with Mplayer/SMplayer in ubuntu

Enable XScreenSaver in Mplayer

Enable ScreenSaver in SMplayer

Resetup Virtualbox Installation

Well, if any error message shows like "no suitable module for running kernel found", it may indicate that the virtualbox installation is not performed well. A resetup may be required, this is the way to do it:

[code]sudo /etc/init.d/vboxdrv setup[/code]