Amber Jain's weblog (OLD)

Visit my new weblog at http://amber-jain.blogspot.in/

Posts Tagged ‘Linux

Using kqemu in debian

leave a comment »

kqemu is not available in any of official debian repos. (Google “kqemu” if you dont know what kqemu is. Also kqemu on wikipedia).

So, if your machine doesnot supports KVM (like mine), you’ll most probably feel the need of kqemu. To install kqemu on debian (confirmed on lenny), follow these:

NOTE: Run all commands below as root.

apt-get install module-assistant
m-a prepare
m-a update
m-a a-i kqemu

After this, open /etc/modules in you text editor and append kqemu after last line (mind you, there should be no other text in that line) i.e. append this line to /etc/modules:

kqemu

Now, restart your system and launch an OS inside qemu *as root* (kqemu wont be loaded with qemu if you are not root).

That’s it πŸ™‚

Advertisements

Written by Amber Jain

July 1, 2010 at 11:20 PM

Error on debian lenny when updating Virtualbox 1.x to 3.x

with one comment

I’m running debian lenny that was setup from minimal netinst. I had installed virtualbox from lenny repos (http://packages.debian.org/lenny/virtualbox-ose). But then I thought of upgrading to newer version of virtualbox because virtualbox 1.x refused to capture my mouse pointer inside guest OS. So, I added lenny-backports repos (http://packages.debian.org/lenny-backports/) to my /etc/apt/sources.list and did ‘sudo apt-get install -t lenny-backports virtualbox). Then when I started virtualbox 3.x, and tried starting (/booting) any guest OS, I got this error:
Virtualbox error

When I was installing Virtuabox from lenny-backports, the ‘apt-get install’ output was:
http://codepad.org/bjDDof4p
Lines number 90,91,92 and 108, 109, 110, 111, 112 are worth noting in that paste.
(Note: If you want to check out log of output from ‘apt-get install’ on debian, goto /var/log/apt/ and open term.log in your text editor as root)

I then tried finding some help on #debian at irc.freenode.net.
User ‘qq-‘ there suggested that I try rebooting. When I rebooted, I got this message in debian boot messages scrollback:

Starting Virtualbox kernel modules. No suitable vboxnetflt module for running kernel found. Failed

After some discussion, users ‘qq-‘ and ‘jpinx-eeepc’ suggested that I try installing linux-image-2.6.32-bpo.5-686 (you can see mentions of this linux kernel version in the paste linked above). So, I did ‘sudo apt-get install -t lenny-backports linux-image-2.6.32-bpo.5-686’.
When I started Virtualbox this time……wooohooo NO ERRORS THIS TIME πŸ˜€

So, in short, install the latest/stable/recommended linux kernel version if you get a similar error.

Written by Amber Jain

June 21, 2010 at 3:47 PM

Recursively search sub-directories in a directory to delete a file with a specific name

leave a comment »

Hello,

@Windows OS users: Sometimes when a malware simply installs itself recursively in all the sub-directories (starting from root i.e. C:) with the same name, you need to delete each file. Manual deletion is not usually possible when there are thousands of malware files. This could prove useful to you.
And yes, use some ‘better’ OS if you can.

On ##unix at irc.freenode.net, someone (justinko) asked a question that goes like:
Que: How to recursively search all sub-directories in a directory to delete a file with a specific name?

Answer: Rather than providing only the answer, I prefer putting the complete IRC log here (mind you, ‘justinko’ and ‘Riviera’ are the nicks of persons involved in this conversation):
justinko how do I delete a file in every sub directory?
justinko im in a directory that has directores, and inside those directories there is one file that needs to be deleted
Riviera with a particular name?
justinko yes
justinko I know the exact file name
Riviera okay
Riviera find directory/ -type f -name 'exact_filename' -exec rm -f -- {} +
justinko is find a command?
Riviera yes
justinko the sub-directories are all named differently
Riviera some finds (actually I only know about GNU find) even have the primary -delete
Riviera yes
Riviera i figured
Riviera The find command I gave you recusively checks all files in the "directory/" hierarchy for files with the name "exact_filename",
Riviera executing the command "rm -f --" with the found pathnames as parameters.
Riviera recursively*
Riviera If you want to learn more about find, read this: http://mywiki.wooledge.org/UsingFind
Riviera note that some of the examples given there are related to the bash-shell.
justinko damn that worked
Riviera I'm glad :)
justinko what is - type f ?
justinko I know rm -f is "force remove"
Riviera restricts the filetype to "ordinary files"
justinko k
justinko what does {} mean?
Riviera so that even if you'd have directories with the same name as the files you wish to remove, would be left alone
Riviera when find starts the command given after the -exec primary
Riviera (which, in this case, was "rm")
Riviera it replaces the {} with the pathnames it found.
Riviera the + says to put many of them
justinko amazing
Riviera with a \; instead of a +, one rm would be started per file
justinko are you a system admin by job?
Riviera but since rm can remove more than one file at a time ... using "+" is more efficient
Riviera no, i'm not :)
Riviera i study humanities ,)
Riviera am sorry, need to leave now, quite late here :)
Riviera nite :)
justinko thank you for the help!
Riviera :)

πŸ™‚

Written by Amber Jain

November 12, 2009 at 5:13 AM