Category Archives: Linux

Noida Linux User Group Second Meeting

The Noida Linux User Group will host it’s second meeting between 12 noon and 3 pm on 29th January at the third floor Barista at the Great India Place.
Hope to see you all there during the event.

For more information, visit http://www.facebook.com/event.php?eid=188477917835011

cheers,
Dhruwat aka unitedroad

Noida Linux User Group

I have been lazy about it, no I have been like an old-trunk-not moved-since-ages about it, but now I am definitely going to get it rolling. Now I finally have atleast one person who thinks it’s a good thing. He’s someone I know from work, who has a real penchant technology and activism, unlike me who is super lazy.
I am also trying to get in touch with a few people on the the social networking sites, primarily outlook, and possibly the technology forums which people from this area would often visit.
Cheers,
unitedroad aka Dhruwat Bhagat

Edit: Noida Linux User Group now has a landing page at http://www.freeyoursource.org/noidalinuxusergroup and its community page at http://www.facebook.com/group.php?gid=151278131564633.

My troubles with dhcdbd, dhclient

When my Ubuntu 1.86 GHz Core Duo box went down, I tried to ssh to it through my OpenSuse box. For this, I reinstalled the dhcp daemon, dhcpd to the latter. But now, I have another problem with this OpenSuse box.

Ever since I reinstalled dhcpd on OpenSuse, everytime the networkmanager tried to get an ip address from dhcdbd – the dhcp DBUS daemon, it recieved a link local address. After going through the system log, I found out that the dhclient didn’t accept the command string used by dhcdbd to execute it. It just exited with the usage details everytime dhcdbd ran it at the request of the networkmanager to get the new ip address.

Then I realised since dhclient also got reinstalled along with the dhcpd, this might have caused the problem. However now I needed to know what that command string was and needed some way to find that out. This is where Snoopy helped me. After installing it and digging through the system log, I found out that dhcdbd ran dhclient with -H parameter that is used to pass the domain name.  Since the installed version of dhclient didn’t recognise this -H option, my networkmanager never got a new ip address. So it helped me resolve a part of the problem.

Only a part of the problem since it seems the my version of dhclient takes network interface down on the -x option, which is also passed in the command string. It seems to me that this -x option does something with the dhclient scripts but I am not sure what. Online help on this seemed a little vague to me so if someone reads this blog and knows about this then please, please, comment about this.

Problem: Log the details of all process ever run in system uptime. Solution: Snoopy

Linux landscape doesn’t seem to provide an out of the box facility that provides you the details of all the processes that have ever been run during the system uptime. Someone at ubuntu irc on freenode told me about Snoopy.

It has a shared library that provides a wrapper about the execv and execve system calls and logs the details using syslog. These details include the process ID, session id, the execution arguements and the id and the name of the user who executed the process.

This is achieved by appending its shared library’s path to /etc/ld.so.preload during the installation so its loaded before the libc objects when a process makes the execv/execve system call.

This tool proved very nifty for me in debugging a problem I was having with dhcp on my linux box running SUSE 10.2.

There have been no new updates to it in last 5 years. And it has a TODO list which includes finding out why logging the execve system call needs a workaround even though it internally calls execv. It also fails to run firefox which seems to have a problem with something between /etc/ld.so.preload and an audio related file in /proc. I’ll edit this blog with its details after finding more.

And actually I would like it to support a few more features . Such as a conf file with the options for what should be logged and to which file. The latter might mean using some other logging facility or adding one of its own to it, but I would find it very useful. For instance, I might want to see the snoopy logs for the past month by the day, letting me know if something odd ran on my computer. Syslog sometimes gets too cluttered with alot of noise for this.  Also, I might want to add the the functionality to get snoopy details through a socket rather than a file, making it easier to get these details from a remote computer.

But, I think there will be some features the snoopy can add which may or many not include the ones I mentioned above. I think we should pick up the thread and continue the work from where snoopy developers stopped.

I think a proc file for the basic snoopy functionality might not be a very bad idea. As clumsy as the procfs is found by many Linux kernel maintainers these days and this treads on the policy-in-the-kernel issue, many people just find it very convenient to use.

If you have used snoopy before, tell me if you think it should be developed furher or you think its just good enough as it is for what its meant for. If you haven’t and feel this would be useful for you, tell me about how you found/liked this tool.

How about a Noida Linux User group?

Noida is an IT hotspot in the North India, next only to Gurgaon, but we still don’t have a functional Linux group here. I think Noida would do very well with such an effort. A LUG would be a perfect way for people in the IT field to give something back to the community.
We could learn so much from each other’s experiences. The Linux/Unix environment is so vast that probably even a linux admin by profession can not learn everything about it all on his own in one lifetime. We could share simple tips and workarounds and even new ideas and possible new projects.

An LUG can also be a place to initiate interested newbies into Linux.
Because even though the free software/OSS community has done alot to make Linux easy to use for the masses, some people are still scared of alot of things the end user Linux distros throw at you.
People usually get accustomed to this if they dig around on the net or have someone to help, but many just give up way early. Like some times its impossible to do repair work when your installation goes horribly wrong unless you go to the command line which scares many. We could help many here if we make an effort.

The people at Jaypee Institute of Technology had made this effort before, but its no longer functional. Even the URL(http://www.lug-jiit.tk) takes you to a junk search site these domain name providers put up when your domain name expires. I have seen this with the college organizations a few times, having been involved with some of them. They are started with alot of enthusiasm but gradually as the old people tend to leave, the enthusiasm fizzles out.

But maybe this effort will would be more successful. Anyone who runs into this site online or anyone I know who I have forced to see it, get in touch so that we can plan something out.