How to enable telnet in a Linux server?
Telnet is a network protocol, used to provide bi-directional text-oriented communication facility.
Note: Telnet in is insecure protocol and it is recommended that you use ssh server.
Telnet Server installation
user@techinx$ sudoapt-get install telnetd
root@techinx# yum install telnet-server telnet xinetd
Configure telnet server (turn on telnet server)
If you are using Red Hat / Fedora Linux
The configuration file for telnet is /etc/xinetd.d/telnet. To enable telnet server you need to open this file and make sure disable = no read as disable = yes.
root@techinx# chkconfig telnet on
To start telnet server type command:
root@techinx# /etc/init.d/xinetd restart
How to enable root login from telnet server
Edit /etc/securetty file, In the end of file add pts/0 to enable one telnet session for root. if you need to open more telnet session for root and add more pts/1 pts/2 and so on.
Restart services, you are done!.
Unable to install IBM Installation Manager on RHEL 6.* (64-bit)
There was an issue, with IBM installation manager not able to install or start in RHEL 6.* series. This issue is fixed by IBM and is available in Fix central for download. The fix name is agent.installer.linux.gtk.x86_64_18.104.22.16820831_1216.
If you are using the old IBM installation manager, during install you may face errors like this.
[root@rhel64]# ./install bash: ./install: /lib/ld-linux.so.2: bad ELF interpreter: No such file or directory
Installation Manager is a 32-bit application and requires 32-bit versions of OS system libraries. These libraries are not installed on RHEL 6.0/6.1 x86_64 (64-bit) by default. You must install these 32-bit libraries on your system before you run Installation Manager.
Configure yum on your server, install the required 32bit binaries.
To configure yum on your server refer here https://www.technix.in/local-yum-setup-for-rhel/
after the yum configuration install the dependent 32bit binaries as shown below.
[root@localhost]# yum install gtk2.i686 [root@localhost]# yum install libXtst.i686 [root@localhost]# yum install compat-libstdc++
Once the install is complete. IBM installation manager installation can be proceeded as normal.
How to use proxy server from Linux terminal
In Linux/Unix there is an environment variable called “http_proxy” which can be configured for text based internet sessions. This variable is used by wget, curl, lynx etc.
How to set http_proxy variable
Type the following command to set proxy server
How to set the http_proxy variable globally
add the following lines.
How to I use a password protected proxy while using command line internet
#curl --proxy-user <username>:<password> www.technix.in
Symmetric Encryption Vs Asymmetric Encryption
- Symmetric encryption is the oldest and best-known technique.
- A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way.This might be as simple as shifting each letter by a number of places in the alphabet.
- Symmetric encryption uses the identical key to both encrypt and decrypt the data.
- As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.
Examples of Symmetric Encryption includes: DES, Triple-DES (3DES), IDEA, CAST5, BLOWFISH, TWOFISH.
- This encryption technique is born from the disadvantage of Symmetric Encryption.
- Asymmetric encryption, in which there are two related keys–a key pair(A public Key and a Private Key).
- A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it.
- Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key.
- Any message that is encrypted by using the private key can only be decrypted by using the matching public key.
Examples of Asymmetric Encryption includes: RSA, DSA.
How do I rebuild grub after Windows 8 installation
Recently I had updated my System which was dual booted (Debian and Windows 7) from Windows 7 to Windows 8, During the installation process I had messed up with Grub boot loader. Once after the upgrade my Grub has vanished and I was able to boot up only Windows 8.
A bit disappointed thinking about windows Not giving an option to Select a boot loader of my choice, I started looking back on my System admin skills and finally here’s how I recovered my Boot loader.
1. Boot from a CD or Live USB.
2. Go to Linux rescue.
3. Get the partition tables for the hard disk devices using fdisk command, and find out the linux root file system, in mycase it was /dev/sda6
# fdisk -l
4. mount the root filesystem using the mount command.
#mount /dev/sda6 /recover
5. mount /proc and /dev filesystems
#mount -t proc none /recover/proc
#mount -o bind /dev /recover/dev
7. Now chroot to the mounted root filesystem
8. Now do grub-install to reinstall grub
9. Grub-install finished without error and I was able to dual boot from Grub after a Reboot.
Here comes Ubuntu 13.10!
Ubuntu 13.10 Code named “Saucy Salamander” is released for the desktop, server, phone, and cloud – download it here.
Ubuntu 13.10 introduces the first release of Ubuntu for phones and Ubuntu Core for the new 64-bit ARM systems (the “arm64” architecture, also known as AArch64 or ARMv8), and improved AppArmor confinement. In addition to these flagship features there are also major updates throughout.
Ubuntu Server 13.10 includes the Havana release of OpenStack, alongside deployment and management tools that save devops teams time when deploying distributed applications – whether on private clouds, public clouds, x86 or ARM servers, or on developer laptops. Several key server technologies, from MAAS to Ceph, have been updated to new upstream versions with a variety of new features.
Maintenance updates will be provided for Ubuntu 13.10 for 9 months, through July 2014
Users of Ubuntu 13.04 will be offered an automatic upgrade to 13.10 via Update Manager. For further information about upgrading, see:
For release notes visit here
Free hands-on experience with Red Hat Storage Server on the AWS cloud.
Red Hat has announced new Red Hat Storage Test Drives through Amazon Web Services (AWS), giving enterprise customers a free hands-on experience with Red Hat Storage Server on the AWS cloud. As per Red Hat blogs the Test Drives to be available later this month.
Red Hat Storage Server running on the AWS infrastructure offers customers an open software-defined storage platform providing a highly-available storage solution on AWS with unified file and object access..
Red Hat Storage Test Drives on AWS will offer the opportunity for enterprise customers to substantially increase time-to-value and help them deploy cloud storage more easily. Customers who are also interested in building hybrid clouds that span on-premise and off-premise resources to deliver the best of both worlds: public cloud economics and agility, optimized for private enterprise needs such as audit, risk management, and strong policy management. Hybrid clouds that are truly open can deliver strategic advantages to the business by redirecting resources from lights-on to innovation.
Red Hat Storage Test Drives labs on AWS have been developed by Red Hat for educational and demonstration purposes. Each test drive lab will include up to 5 hours of AWS server time. Within minutes enterprise customers will be able to create and experience a secure multi-terabyte storage solution that can be accessed using different POSIX compatible protocols like NFS, SMB, and GlusterFS clients. Pre-configured use cases in the Test Drives include:
- High availability and business continuity to provide high levels of data security with built-in replication and self-healing capabilities;
- Secure enterprise file sharing and collaboration to reliably store and retrieve files from a variety of devices by creating your own enterprise drop box;
- Large file and object storage to take advantage of cloud network-attached storage (NAS) to cost-effectively manage unstructured data at-scale; and
- Media content delivery and storage to quickly serve and scale multimedia content to mass audiences.
is there an Office communicator for Linux?
Most Linux users come across a question “is there an office Communicator for Linux?”
And the answer is “Yes, We have PIDGIN”
For Linux users Pidgin (IM Client) provides access to the Lync functionality and therefore serves the purpose, even though we don’t have features like audio/video calls and sharing.
For making Pidgin to work with the latest Ubuntu Release of 13.04, follow the below steps
1. Install using:
$sudo apt-get install pidgin pidgin-sipe
2. Run Pidgin and click on Add button
3. Select “Office Communicator” from the protocol list. Fill out the fields as necessary:
Password: Your Lync password
4. Once authenticated with the server, we should be able to see out Contacts.
Wine 1.6 Released
Among the wine 1.6 highlights are OpenGL DIB support, RandR 1.2/1.3 support, the Mac driver for not having to rely upon X11, Direct3D off-screen rendering, early 64-bit ARM support, dynamic device support, a Direct3D shader compiler, multi-channel ALSA audio handling, and thousands of other changes.
For more details visit wine wiki
The source is available from the following locations:
Binary packages for various distributions will be available from:
You will find documentation on http://www.winehq.org/documentation
You can also get the current source directly from the git
repository. Check http://www.winehq.org/git for details.
Features below, taken from http://www.winehq.org/announce/1.6
Working with Oracle HTTP Server
In this blog i’m covering some basics on Oracle HTTP server(OHS) like
- Checking OHS status.
- Starting, stopping and restarting OHS.
- Creating an Oracle HTTP server component.
- Deleting an Oracle HTTP server component.
Checking OHS Status
We can determine the status of OHS by using the opmnctl command
$ORACLE_INSTANCE/bin/opmnctl status Processes in Instance: instance1 ---------------------------------+--------------------+---------+---------+------- ias-component | process-type | pid | status | Ports ---------------------------------+--------------------+---------+---------+------- ohs1 | OHS | 4789 | Alive | https:1000, https:4444, http:7778
Starting, Stopping and restarting OHS
To Start use: >
To Stop use: >
$ORACLE_INSTANCE/bin/opmnctl stopproc process-type=OHS or use
To restart: all Oracle HTTP Server components use:
$ORACLE_INSTANCE/bin/opmnctl restartproc process-type=OHS
Creating an Oracle HTTP server component
The syntax for creating a Oracle HTTP server component is
$ORACLE_INSTANCE/bin/opmnctl createcomponent -componentType OHS -componentName component_name
For eg: to create an Oracle HTTP Server component named
ohs1, use the following command:
$ORACLE_INSTANCE/bin/opmnctl createcomponent -componentType OHS -componentName ohs1
When you create the Oracle HTTP Server component, ports are automatically assigned. However, you can use the following parameters to specify the ports of your choice:
-listenPort: HTTP listening port
-sslPort: HTTPS (SSL) listening port
-proxyPort: Proxy MBean port internally used by Oracle HTTP Server to communicate with Fusion Middleware Control
Deleting an Oracle HTTP server component
The syntax for deleting an Oracle HTTP server component using opmnctl is
$ORACLE_INSTANCE/bin/opmnctl deletecomponent -componentName component_name
For eg: to delete an Oracle HTTP Server component named ohs1 use the following command:
$ORACLE_INSTANCE/bin/opmnctl deletecomponent -componentName ohs1