Samsung Vibrant

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sosreports and Notepad++ in Windows

I learned a new trick yesterday. It all started when a rogue service on some of my RHEL servers would start even though it was configured not to start. The rogue service was iptables. I don't need iptables running on my servers since they don't talk to the web, so after initial installation I turn it off using the command: chkconfig iptables off & chkconfig ip6tables off.
This works pretty good most of the time. Except for where I work, we are very prone to finding bugs if they exist.
So I begin my investigation.
First things first, can I duplicate the issue? Yes. Every reboot.
Ok, now to find out why. I pull an sosreport from the server. Copy it to my Windows 7 laptop.
My goal is to review pretty much every config file in the report looking for references to iptables.
This is starting to look nasty... This means I need to open each file in an editor of some sort.
Well this is where I learned a new trick. I opened up notepad++. Not paying attention to what I was doing, instead of dragging a single file or a group of files to the editor, I grabbed a folder, /etc/ in this case and dragged it to notepad++.
Oops, well, let's see what happens.
Notepad++ did something unexpected, but very much to my liking, it opened each of the files in the folder. It was great, hit cntl+f to search and search each file for iptables.
A few instances found, not what I was looking for. So I continued to do so with each folder... I was pleased with Notepad++'s ability to open each file in the folder.
It was great and sped up my work considerably. I still don't know why iptables continues to start at each boot, but oh well, I opened a case with Red Hat to get that issue solved, still working with them to get an answer.
I will post an update once the issue is resolved. I am sure that Red Hat if anyone can solve this weird issue for me.

Linux and grep

At work the other day, I was given a new task. I was to identify the brand and serial number of each of the servers I manage. Most of the servers are blades.

I had a couple of options, I could run over to the datacenter and physically look at each server, I could use the blade chassis web management gui, or I could use the OS to pull the needed info.

As it turned out, it took a little of all 3 options to gather all of the info. But this post will be about the last option. How do you pull server specific information from the OS? In this case, the OS is Red Hat.

Well, this is a simple process. First, we will use lshal. This command will tell us about everything that Red Hat sees hardwise during bootup. If you have ever used or viewed the output of lshal, you know that it can be a daunting task to find specific information. This is where grep comes in handy. Grep is used to parse the output of a command. We just pipe the output of the lshal to grep and give it a search string. A good example would be something like this:


cat /etc/fstab | grep sda
# / was on /dev/sda1 during installation

That was cool, now try running lshal and grep for serial:

The command will look like this

lshal | grep serial

Our output will look something like this:

lshal | grep serial

  system.board.serial = '123490EN4XXX15'  (string)

  system.hardware.serial = 'XXXX93DQCX1628'  (string)

  battery.serial = ''  (string)

Great, I now have the serial number of my system, But what brand is my computer?

Try this:

lshal | grep vendor

And we get this:

system.board.vendor = 'SAMSUNG ELECTRONICS CO., LTD.'  (string)

  system.firmware.vendor = 'Phoenix Technologies Ltd.'  (string)

  system.hardware.primary_video.vendor = 32902  (0x8086)  (int)

  system.hardware.vendor = 'SAMSUNG ELECTRONICS CO., LTD.'  (string)

  battery.vendor = 'SAMSUNG Electronics'  (string)

  info.vendor = 'Intel Corporation'  (string)

  pci.subsys_vendor = 'Samsung Electronics Co Ltd'  (string)

  pci.subsys_vendor_id = 5197  (0x144d)  (int)

  pci.vendor = 'Intel Corporation'  (string)

I now know that the vendor of, in this case my netbook is Samsung.

Hope this was helpful.

What are some examples of how you have used grep in the past?

Thanks for stopping by, and be sure to leave me a comment.

Adventures in linux

I am an Ubuntu fan. More specifically, Xubuntu, which uses XFCE instead of the more popular Gnome or KDE. I'm not a Gnome or a KDE hater, XFCE looks a lot like Gnome in my opinion. It just doesnt't have all the bells and whistles that Gnome or KDE has. I think I liked KDE so much, because since DOS 6.22 had gone away, I had become used to the look and feel of the Windows Environment and KDE was very much like Windows. KDE was great, it had many bells and whistles, and was just fun to use.

When I first started in Linux, I had become bored with Windows. It no longer held any attraction for me. So I was taught on Gentoo. A very powerful distro. Highly customizable, and if you knew what you were doing, optimized specifically for you hardware. This same thing can also be said for pretty much most of the distro's out there. I learned a lot diving head first into Gentoo, with the assistance of a very patient friend.

After several months, I was very efficient with the install process. My problem (which was myself) was I like to tweak and change things. This caused me many, many, many late nights reinstalling. But, I learned a lot about Linux in the process, and had a lot of fun doing it.

After about a year, I decided to start playing around with other distros. I liked the way a lot of them looked, SUSE was nice, but not for me, Mandriva, I wasn't crazy about. Slackware, scared the devil out of me. CentOS and Fedora where cool, but still not for me.

After downloading and burning and testing 30+ different live cd's, I ran across Ubuntu 5.04. It was awesome. This is the distro I used to completely rid my home of Windows. I could do everything I needed to and all of it was done in linux, and if I couldn't, well, I just got over it. It was usually something trivial anyway.

It became even more awesome when I learned about Kubuntu.
Being that I was a big fan of KDE, Kubuntu rocked. And that is what I used until I bought my first netbook. The ASUS EeePC 701. This little experiment shipped with a 4 Gig SSD as the internal drive. Kubuntu just wouldn't fit. After several google searches, I ran across XFCE. Lightweight, efficient and minimal. This led me to Xubuntu, which I believe is perfect for a netbook.
All the power of Linux, without the overhead of some of the more popular desktop environments. It was a good match for a netbook.

I still use Xubuntu to this day, why, it just works. I don't need all of the eye candy, and eye candy may look good, but I think it overpowers a lot of the netbooks. I like to be able to use my resources, not wait for the computer to catch up to me.

While I am pretty sure that my current netbook, the Samsung NC10, can handle the eye candy, I just don't want to give up the resources for it.

Do I hate Windows, not really, I still use it on my laptop issued to me from work. I don't complain about it (not very much anyway) , I just want everything to work when I turn on my computer. While no OS is perfect, you just may be missing out by not giving linux a spin. Most of the distro's are free, support can be found in many forums, and there are tons of people willing to lend a helping hand.
I think that Linux is considerably more user friendly now than it ever was. Go ahead, give it a try.

A good place to start is here:
http://distrowatch.com/
You can find the most popular versions with links to download.
Or if you need a distro to perform a specific task, whether it be audio editing, video editing, or security, there is a distro for that too.
So what are you waiting for, dive in and give it a go.

Enjoy.

Linux and SSH

Sometime ago I built myself a media server. This is a Linux box running Xubuntu and setup to stream media to the XBox 360, the Western Digital Media Player and connected to the audio in on the stereo. I searched and searched for a good howto so I could setup VNC on my server so I could control the media player. In this instance, GMusicBrowser, just because it is light weight and quick.

Then it dawned on me.... What am I doing??? I could use ssh and X11 forwarding. 

So that is what I did. 

I already had opensshserver installed on my server. X forwarding is enabled by default. So no config to mess with. 

Just simply log into the server using a command such as this:
ssh -X username@192.168.1.12 (Note that is a capital "X")

Then while connected just type in the name of the app you want to run. In this example it was gmusicbrowser. The app opened up on my local laptop and the output went to the stereo. 

That was all it took.

Here is how you can accomplish the same thing.

Once you have Ubuntu installed and patched, run this command:

sudo apt-get install tasksel

Followed by 

sudo tasksel

When you run tasksel you will get a box opened up in your shell. 

Using the arrow keys scroll down to openssh server.

Select this by pressing the space bar.

Then tab to OK and press enter.

This will install the needed packages to make your Ubuntu computer accept ssh connections.

This is all you need to do. Then you can go to your other computer and connect using a command just like the once I used above. 

ssh -X username@192.168.1.12

If you have a firewall enabled you will need to make sure that port 22 is open to allow your ssh traffic to your server.

That's it, you're all done and ready to run some apps.

Linux SSH and the Screen command

The screen command, what is that you ask?
That is a good question. The screen command comes standard with most linux distributions. Ok, So what does it do you ask? Well it is quite simple and extremely handy to know.

Given scenario: You are tasked with copying a large amount of files from an external USB drive to one of your linux file servers. The server has no GUI installed, so you have to use the CLI. So you fire up putty and mount the drive and then you start the file copy. It is close to time for you to leave the office for the day. You know that if you close the putty session, your file copy will stop. This sucks, you figure you still have a couple of hours to wait before the copy finishes. You need to leave, and the files need to be in place by the time you get to the office in the morning. This is where screen come to the rescue.

man screen
Screen is a full-screen window manager that multiplexes a physical terminal between several processes (typically interactive shells). Each virtual terminal provides the functions of a DEC VT100 terminal and, in addition, several control functions from the ISO 6429 (ECMA 48, ANSIX3.64) and ISO 2022 standards (e.g. insert/delete line and support for multiple character sets). There is a scrollback history buffer for each virtual terminal and a copy-and-paste mechanism that allows moving text regions between windows.

Instead of immediately starting yout copy session once you have your putty session established, try this.
Start your putty session, then just type in the command "screen". You will be shown an intro window, just press space to make that go away. You now see your command prompt. Start typing, start your file copy.

Oh, you just found out you need to modify your firewall and the file copy hasn't finished yet, no worries, screen can assist you here too. Instead of opening a new putty session, just press ctrl+a and the c. This will create a new session. You will see a new prompt appear, start typing away.
While watching the logs to make sure you opened up the correct ports, you need to check on your file copy, simple. Press ctrl+a and the p to return to your previous session. To go back, press ctrl+a then n to hop in to the next session you created. Seems simple enough.

Now it is time for you to shut down for the day. Press ctrl+a then d to disconect from screen. You will return to your original session where you can then safely exit putty.

You make the commute home. Once home all safe and sound, you decide to connect to the office and check your file copy. Once again we fre up putty. Now we just need to reconnect to your screen session. Just type in screen -r. You will connected back to your screen session.
Well that was easy. There is much more functionality in screen. This is enough to get you going, and I highly recommend you spend some time looking around in the man pages to see what else you can with screen.

So leave a comment and let me know what you think. How has the screen command helped you?

Linux file copies

I frequently use external USB drives to transfer large amounts of data from my laptop to my server. I find it is faster than using my wireless network. While doing all of these transfers, I soon learned that file copies finish faster when through the CLI. Why you ask, I don't really know, I assume it has something to do with the overhead of the desktop environment, but that is just a guess.
So I start my copy session, it may be music, movies or ISO's, just whatever data I feel like messing around with that particular day. I used this command:
cp /path/to/data/* /path/to/destination
This works great, for all the files in a folder, it does not however copy subdirectories or the contents of the subdirectories. To copy this, we need to add the -R switch to our copy command. It now looks like this:
cp -R /path/* /destination/
This looks and works better, until you move your laptop to the other side of the room and forget to move the USB drive along with the laptop, oops, I just disconnected my drive during a copy...
Now what, delete the folders from the destination and start over, that is what I used to do, then I learned some helpful switches, now my copy commands look like this:
cp -uRav /path/* /destination/
All of the switches are important here, the "u" tells the copy command that it should only copy over the destination file if the source is newer or the destination file is missing, the "v" is verbose, so you can watch the file list scroll up the screen while the copy process is working. The "a" is for archive, this makes sure that the destination has the same attributes/permissions/ownership as the source file.
Just another lesson learned.

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Ubuntu and Updates

I was talking to another Ubuntu user today and realized that I sometimes do things that others may find useful. In this particular instance, Ubuntu updates. There are a couple of ways to apply updates to your system. You can go the GUI route and use the update manager, or Synaptic Package Manager, or you can use the CLI commands. I have been using Linux as my primary OS at home for several years now. I am by no means an expert, but I do know my way around the CLI. The sequence I used to go through to apply updates to my system was to open a console and start typing away. At first I would run each command individually. So I would run the following commands:
sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get autoremove -y
sudo apt-get clean
The 1st command will update the package list with new versions of the packages available.
The 2nd command will actually apply the updates to the system.
The 3rd command will remove any packages that were left behind after removing a package.
The 4th command will remove all of the downloaded files that were needed to apply the updates.
You can look in /var/cache/apt to see how many different packages have been downloaded. This is a wise thing to do if you consistently run low on disk space.
After a while, I learned I could type in a long string of commands to accomplish the same thing, it looked like this:
sudo apt-get update && sudo apt-get upgrade -y && sudo apt-get autoremove -y && sudo apt-get clean
While this will provide the same results as running the commands individually, I then made the process a bit easier. This is how:
I created a file called updateme in my home folder, if using the CLI you can do this:
touch updateme
This will simply create the file. Once the file is created, you then edit the file with your favorite editor, in my case, nano.
nano updateme
You then take the 4 commands shown above and copy them into the file.
Now we need to make the file executable. To do this we run this command:
sudo chmod 755 updateme
You can now execute the file by running this command:
./updateme
If you regularly forget to type in ./ in before the command you can do this:
cd into /bin
Then run this command:
ln -s ~/updateme
This will create a shortcut to updateme in the /bin folder. Now that the shortcut is in /bin, all you have to do to run the file is type in the name like so:
updateme
I decided I like this method and use it an all of my Ubuntu systems, it saves time and keystrokes, and prevents you from forgetting any steps, like removing the cached files after each round of updates.
I understand that this may not be the absolute correct way to do this, but this demonstrates one of the greatest aspects of linux in my opinion, multiple ways to pretty much accomplish everything.
I hope you find this information helpful, if you see something that can ease the process a bit more, drop a comment and let me know.

Thanks for reading, hope you enjoyed it.

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A little about me

Hello,
I am new to this whole blogging thing, well not really but sorta kinda. I have been reading other people's blogs for a while now. I am just new to writing my own. So let's see how well this works out. I am hoping to be able to use this to share software and hardware experiences with the interwebs.
I currently own and use a Dell Latitude D610 and a Samsung NC10 Netbook. While both are great pieces of machinery, they are a bit outdated. They do however work very well. I run Xubuntu 10.10 on the netbook and dual boot the Dell with Windows XP and Xubuntu 10.10. Although I am not a huge fan of Windows, there are some apps I just don't care to run in wine and have not yet found a suitable linux equivalent.
Most of what I do, is done with the Netbook, just because of the size and the battery life. The Dell I use to run Eclipse to "try" and learn something about Android development. I will post more about this later.
I use Xubuntu becuase I prefer XFCE over Gnome or KDE, especially on lower powered or outdated equipment. XFCE has less overhead than the 2 other desktop packages. It is fairly straightforward to configure, and as for the hardware, everything but the special function keys work right from the start. I don't use them anyway, so it hasn't been a big deal. This goes for both the Dell and the netbook, I have read about ways to fix each, but why bother if I don't use them anyway.
Anyway, that is my environment, and where most of my content will come from. As I discover new ways to accomplish tasks, or great ways to simplify large tasks, that information will be shared here.
So check back often, there just may be something useful to you on here.

My first Blog

Hello world,
Welcome, sit, read, enjoy your stay.
Throughout the life of this blog I will be posting my Linux, Windows and Android exploits. This will not only be a place for me to store information that I find useful, but a place for me to share said information.

That's all for now, so check back tomorrow for more content.