Linux

Remove CD-ROM from apt-get repositories

I just got my hands on the new Debian 7 DVDs and installed a fresh server install. Now up and running its time to use aptitude to install some software when I kept receiving the following message:

Media change: please insert the disc labeled ‘Debian GNU/Linux 7.0.0 _Wheezy_ – Official amd64 DVD Binary-1 20130504-14:44’ in the drive ‘/media/cdrom/’ and press enter

Fixing this was a simple task. All that was needed was to remove or comment the reference to the CD/DVD from the /etc/apt/sources.list

Example: #deb cdrom:[Debian GNU/Linux 7.0.0 _Wheezy_ – Official amd64 DVD Binary-1 20130$

steps are:
log into your debian system
sudo nano /etc/apt/sources.list – sudo if you are not logged in as root
#comment out the line in the above example – saving the file (ctrl x) enter y for yes

 

Debian Wheezy Released

Hello all,. Just a reminder and a notice to those who have waited many months of development. The Debian Project has finally released #wheezy

For those of you not in the know: Debian is a free operating system (OS) for your computer. An operating system is the set of basic programs and utilities that make your computer run.

This new version of Debian includes various interesting features such as multiarch support, several specific tools to deploy private clouds, an improved installer, and a complete set of multimedia codecs and front-ends which remove the need for third-party repositories.

So get your torrent clients out and start your downloading.

Attach and Reattach to screen session

While using ssh to connect to my home systems to mange my servers (such as Minecraft) I use screen to keep my session(s) open so that if I get disconnected or simply forget and close my putty session I can later resume.  I sometimes find myself in the situation where I go home and later want to attache to my session to only find that I am already attached and this is where I again use screen to join the session that is already in progress.

Here are some sample commands I use normally while during my daily activities.

Attach the running session of screen
screen -r

Attach a specific screen session, you need to use screen -ls to list the running screen’s sessions.
screen -r [name]

and if you are attaching again (reattaching to a session in progress)
screen -d -r

CrashPlan on headless debian server

I had been interested in using a backup solution for my photos when I came across CrashPlan. The price for one was a quick sale and the idea of being able to backup “unlimited” data from a single computer just seemed to fit what I had been looking for.

I recently changed my home file server (NAS) to OpenMediaVault based on Debian server which I must say is working out and exceeding my expectations. The only thing missing was how to get my data offsite. Taking advantage of CrashPlan seemed to be the perfect solution.

I preformed the following steps to get everything I needed up and running:

Step 1 – I installed CrashPlan on my windows machines so that I could setup an account. The software can be obtaining at http://www.crashplan.com

Step 2 – I logged into my NAS as root and downloaded the latest version of CrashPlan for Linux using wget. (wget http://download.crashplan.com/installs/linux/install/CrashPlan/CrashPlan_3.4.1_Linux.tgz)

Step 3 – I extracted the tgz and ran the installation:
tar -xvf CrashPlan_3.4.1_Linux.tgz
cd CrashPlan-install
./install.sh

Crashplan will  install and if Java isn’t install already (In my case it wasn’t it will prompt you to install. Follow all the installation steps. You should just answer ‘yes’ to each step. Once the installation has completed it will inform you that the service has started and some info about forwarding ports to manage the service remotely.

The ssh forwarding should look something like this: ssh -L 4200:localhost:4243 user@ip.of.server
I did this in putty by clicking on change settings and under connection > SSH > Tunnels

You will also need to change the setting of your client to connect to the forwarded port so that you can manage the backup service. This is done by going to the following path “C:\Program Files\CrashPlan\conf” and modifying the file ui.properties as such:

#serviceHost=127.0.0.1
servicePort=4200
#pollerPeriod=1000 # 1 second
#connectRetryDelay=10000 # 10 seconds
#connectRetryAttempts=3
#showWelcome=true

#font.small=
#font.default=
#font.title=
#font.message.header=
#font.message.body=
#font.tab=

Save this and open the client. You will be prompted to log in. This time the folder you manage will be on your Linux system. Select what you want to and let the uploading begin

– Jermal 

“Permissions are too open”

No man is above the law and no man is below it: nor do we ask any man’s permission when we ask him to obey it. – Theodore Roosevelt

You are attempting to automate your ssh session to a remote system using keys and you get the following “Permissions are too open” message.

The problem is, that the private key you are using must remain private. If you permit others to read it, that condition is not satisfied. So when you type something such as ssh -i ~/.ssh/rsa_key admin@jermsmit.com you get the classic Warning: Unprotected Private Key File!

To change this you simply do the following (make it so only you the owner can read and write to the private key:

This worked for me, it should work for you.

– Jermal

Show List Of Network Cards in Linux

Here is a question I got not so long ago.

Jermal, How do I go about finding the name and type of network card I have in my Linux installation?

First off, thanks for asking me. I know of a few ways and I’ll list them here. Short and simple. We have the the following commands: ip, ifconfig, lspci, dmidecode, lshw commands. Out of these I only use 3.

ifconfig and ip commands

lshw command is another nice one also

And when feeling a bit fancy you could toss in the lspci command with egrep

And… that is about it. I hope this answers your question

– Jermal

How to get information about hardware on Linux

The dmidecode command reads the system DMI table to display hardware and BIOS information of the server. Apart from getting current configuration of the system, you can also get information about maximum supported configuration of the system using dmidecode. For example, dmidecode gives both the current RAM on the system and the maximum RAM supported by the system.

Here are some sample command use

Find baseboard information

List info about the bios

And here is a list of valid keywords types

As always; I hope this helps some of you. For me these are just notes so I have a place to turn to for reminders.

How do i check which LVM version i’m using.

“bump”

And that is my filler post for the day.

— more info —

Logical Volume Manager (Linux)

LVM is a logical volume manager for the Linux kernel; it manages disk drives and similar mass-storage devices. The term “volume” refers to a disk drive or partition thereof. It was originally written in 1998 by Heinz Mauelshagen, who based its design on that of the LVM in HP-UX.

Use lspci tells me my VGA Memory Usage

“Drugs are a waste of time. They destroy your memory and your self-respect and everything that goes along with with your self-esteem. They’re no good at all.” – Kurt Cobain

Sitting here playing around with some cli I wanted to know how much memory my VGA card was using so to find out I did the following by typing:

root@websvr:~# lspci |grep “VGA

My results was the following
00:0f.0 VGA compatible controller: VMware SVGA II Adapter

I then typed the following lspci command to give me more details:

root@websvr:~# lspci -v -s 00:0f.0 |grep “Memory
Memory at d8000000 (32-bit, prefetchable) [size=64M]
Memory at d0800000 (32-bit, non-prefetchable) [size=8M]

And there I have it. I’m using 64M of memory.

–more info–

lspci is a command on Unix-like operating systems that prints detailed information about all PCI buses and devices in the system. It is based on a common portable library libpci which offers access to the PCI configuration space on a variety of operating systems.

Raspbian Wheezy Squid Proxy

“I am learning all the time.  The tombstone will be my diploma.”  ~Eartha Kitt

Hello Friends, I am back again with an update on my most recent Raspberry Pi (Rasp~ Pi) minimal image; This time around I have added a Squid Proxy Server to the mix. Like that of my previous post I am still running on top of the awesome base setup that just works wonders for me.

I did add some additional tools such a htop, sshfs, cifs utils, nmap, and many more. You’ll just have to give it a go to see for yourself., but let us not get off track. This image is all about the out of the box squid proxy experience. I have done the install (simple for some, not to others) and updated the squid.conf to allow for the typical LAN network access. Don’t worry, I preserved the base configuration file for your review.

Some things I would like you to know:

1. This image boots up, grabs an IP Address from your DHCP network
2. Squid will also start-up on its own (using Google DNS to look up internet addresses)
3. Runs fantasticly on a small home / office network

Link to download this custom updated image: raspbian_wheezy_armhf_squid_jermsmit_20120819.7z
Sorry about the size, there are some things I didn’t clean up’; such as logs etc…

The root password is: jermsmit

–More Info–

Squid is a proxy server and web cache daemon. It has a wide variety of uses, from speeding up a web server by caching repeated requests; to caching web, DNS and other computer network lookups for a group of people sharing network resources; to aiding security by filtering traffic. Although primarily used for HTTP and FTP, Squid includes limited support for several other protocols including TLS, SSL, Internet Gopher and HTTPS – source