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  Server monitoring shell scripts

There are many open source server monitoring software such as cacti and nagios. Besides these, can we write our own shell scripts to monitor them? The shell scripts written by ourselves can fulfill our special requirements better and have a more detailed coverage. Below are some commonly used shell scripts used by Evangelist, an Oracle DBA. 1. Check network gateway traffic #!/bin/bash #network #Mike.Xu while : ; do time='date +%m"-"%d" "%k":"%M' day='date +%m"-"%d' rx_before='...


  Recover deleted file in Linux EXT3 file system

Environment : CentOS 5.3 x86_64, /dev/sdb1 is the data segment /data0. EXT3 file system. Problem : /data0/tcsql/cankao/phpcws-1.5.0/httpcws.cpp is deleted mistakenly and httpcws.cpp is not backed up. It will take much time to rewrite this program again. So we must recover it back. debugfs is feasible in EXT2 file system, but in EXT3 file system, it's not very useful. There is one open source software called ext3grep which can help us recover deleted file in EXT3 file system. The recovery steps a...

4,267 0 0          LINUX EXT3 FILE RECOVERY

  Migrate from MySQL to MariaDB in Ubuntu

The biggest movement of escaping from MySQL in this century starts, openSUSE,Fedora and Arch have started to use MariaDB instead of MySQL as their default database. Many people also dislike the attitude of Oracle on MySQL, so it's reasonable to migrate from MySQL to MariaDB. The whole process is not complicated. Here we share the steps to migrate from MySQL to MariaDB in Ubuntu. Installation procedure: sudo apt-key adv --recv-keys --keyserver 0xcbcb082a1bb943db Modify /etc/a...

3,281 0 1          UBUNTU MYSQL MARIADB

  How to commit code to OpenStack

If you want to make contributions to OpenStack, the best way to start is to help the community with blueprint or submit bug fix. To commit codes, you need to conform to some rules in the community. Work flow Register an OpenID Apply for a CLA certificate Apply for company CLA certificate Update contributor list Join OpenStack Contributors group and OpenStack group Set up SSH Keys Get a blueprint/bug git clone codes to local disk. Configure user name and user email and openid Modify codes in a l...


  Build Hadoop environment in Linux

Hadoop standalone installation: 1. Install JDK Install JDK with below command: sudo apt-get install sun-java6-jdk Configure Java environment, open /etc/profile, add below contents: export JAVA_HOME = (Java installation directory) export CLASSPATH =".:$JAVA_HOME/lib:$CLASSPATH" export PATH = "$JAVA_HOME/:PATH" Verify installation of Java Type java --version, if it outputs Java version information, then Java is successfully installed. 2. Install SSH Install SSH with below command: sudo apt-get...


  Those famous Emacs users

I don't think using Emacs can improve one's programming skills, I don't think some famous people used Emacs before can provide something, either. But these famous people encouraged me to learn Emacs when I wanted to give it up. Here I created a list of famous Emacs users. Most of people in this list are not famous because they developed or used Emacs, but they are famous and also use Emacs. Joe Armstrong -- Erlang's author In The Setup, Joe mentioned that "I write books using XML markup in emacs...

9,592 2 2          HISTORY EMACS

  bash network interface

Some of us may have seen /dev/tcp/<host>/<port> before, is this a special file system implemented in some BSD kernel? Because there is no /dev/tcp in Linux. Actually, this one is implemented in bash. We no need to rely on wget,nc to do network connection. It's very easy to use this interface: bash-4.2$ cat </dev/tcp/ 56188 12-09-18 15:34:26 50 0 0 733.5 UTC(NIST) * bash-4.2$ exec 3<>/dev/tcp/ bash-4.2$ echo -e "GET / HTTP/1.0\n\n" >&3 b...


  About tmpfs

tmpfs is another confusing name in Linux kernel, its implementation is in mm/shmem.c, shmem has no relation to tmpfs at first glance although we know tmpfs is based on memory. We can understand why we use this name by seeing where this is used. In a desktop Linux system, tmpfs is loaded usually: % grep tmpfs /proc/mountsdevtmpfs /dev devtmpfs rw,seclabel,nosuid,relatime,size=1958956k,nr_inodes=489739,mode=755 0 0tmpfs /dev/shm tmpfs rw,seclabel,nosuid,nodev,relatime 0 0tmpfs /run tmpfs rw,seclab...

1,951 0 0          LINUX TMPFS FILE SYSTEM