Password

Direct multi-hop ssh connection

How to use multi-hop ssh connection without needs to ssh multiple times? As a example, you are connecting to server.example.com through proxy.example.com from laptop.example.com as follows: laptop —-> proxy —-> server 2 possible methods: Method 1: Use the similar method as in Directly SSH to hosts using internal IPs through the gateway. Add this to…

Sending emails securely

Sending emails securely is needed for certain situations, such as sending my bank account to my wife, giving my account password to my close friend for a while. How to send it? Regarding the recent US PRISM program, it is an important issue. Seeing your solution, a few of my own popped up. Here are…

Pass-less ssh auto-login problem

I configured the Linux password-less automatic ssh login as in this post . However, it still does not work for me. Any method to check it? The log in log /var/log/secure may give some clue on it. For example: Aug 20 23:16:10 doppler sshd[11143]: Authentication refused: bad ownership or modes for directory /home/useraaa tells us that…

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Where Does Evolution Save Its Data and Configuration Files on Linux?

Evolution is a great personal information management tool that provides Email, address book and calendar tools. Evolution provides many enterprise friendly feature such as native support to Microsoft Exchange connectivity for Emails, address books and calendars. Evolution uses various ways including plain files and dconf configuration systems. This post will give an introduction to the…

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How to Change Linux Account Password Through SSH: A Beginners’ Tutorial

People are sometimes given access to Linux/Unix and asked to change their initial passwords. But for beginners, changing a Linux/Unix password is not an easy task, especially when there is only SSH log on allowed to the Linux/Unix server. This post introduces how to change password of user USER on host HOST remotely using SSH….

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How to Configure Scanner in an HP All-In-One Printer on Linux?

The hplip packages contains all the tools you need to set up the HP scanner. For scanning, you may use the sane and xsane tools. The tricky part to enable the scanner is carefully choose which driver to use from the hplip package. If you choose a non-suitable driver, only the printer will work and…

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Hadoop Installation Tutorial (Hadoop 2.x)

Hadoop 2 or YARN is the new version of Hadoop. It adds the yarn resource manager in addition to the HDFS and MapReduce components. Hadoop MapReduce is a programming model and software framework for writing applications, which is an open-source variant of MapReduce designed and implemented by Google initially for processing and generating large data…

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Directly SSH to Hosts’ Internal IPs Through the Gateway

We have many hosts with internal/LAN IPs like 10.0.3.* behind a gateway and the hosts with LAN IPs can connect to the Internet through the gateway. We used iptables to forward port from the gateway to internal IPs so that users from hosts with Internet connections can SSH to the gateway’s forwarded port to log…

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How to Set Up A Gitolite Git Server – A Ten-Minute Tutorial

I ever introduced seting up git server using SSH or gitosis. However, gitolite is the way to go for managing git servers if you want an lightweight authentication layer. gitolite provides many very usefull features which can control each user’s right on each branch. I set up one gitolite git server and am very happy…