Category Archives: Linux

This is where all my linux pages will live.

Understanding rpm Verify output

Posted on November 14, 2014 by vicki

rpm -V output: S file Size differs M Mode differs (includes permissions and file type) 5 MD5 sum differs D Device major/minor number mismatch L readLink(2) path mismatch U User ownership differs G Group ownership differs T mTime differs

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Differences in useradd command in different Linux Distributions

Posted on November 5, 2014 by vicki

In Ubuntu and Debian: By default, each user in Debian GNU/Linux is given a corresponding group with the same name. In RedHat/CentOS,Gentoo If not specified, the behavior of useradd will depend on the USERGROUPS_ENAB variable in /etc/login.defs. If this variable … Continue reading →

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Basic GIT stuff

Posted on October 24, 2014 by vicki

Git stuff Conceptual description: http://www.sbf5.com/~cduan/technical/git/git-1.shtml **HEAD is the name given to the commit from which the working tree’s current state was initialized. git rebase allows you to pull changes from master into your development branch, but leave all of your … Continue reading →

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Lsyncd installation and configuration

Posted on January 22, 2014 by vicki

Overview This article describes how to use lsyncd as a sync’ing mechanism for multiple web servers data directories. This is only one scenario in which this program could be very useful for our customers. These notes will provide instructions on … Continue reading →

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Allow ssh only as a single user or from specific IPs

Posted on January 14, 2014 by vicki

The following are the relevant config bits in /etc/ssh/sshd_config # disable password authentication globally PasswordAuthentication no Either by username: # now re-enable it down at the very end of the sshd_config file like thus Match User rack PasswordAuthentication yes or … Continue reading →

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WordPress Stuff

Posted on January 13, 2014 by vicki

To change the admin username in WordPress: 1)Go into your phpmyadmin, and click on “Databases.” 2)Click on the name of your database. 3)Click the “Browse” icon next to wp_users. 4)Click the edit icon next to admin – should be first … Continue reading →

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Regular Expression Notes

Posted on January 1, 2014 by vicki

Explaining the following regular expression: (\d(3,4)[.-]?)+ ( starts a capturing group \ escapes the following character d end character shorthand (match any digit in the range 0 through 9 with \d) { open qualifier 3 minimum quantity to match , … Continue reading →

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Diagnosing SSL received a record that exceeded the maximum permissible length

Posted on December 19, 2013 by vicki

If you setup an ssl cert but are getting the following: SSL received a record that exceeded the maximum permissible length. 1) Check that netstat -ntlp shows httpd listening on 443 2) Check that port 443 is open in the … Continue reading →

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Overriding php.ini values locally

Posted on December 11, 2013 by vicki

php directives are listed here: http://www.php.net/manual/en/ini.list.php Modes determine when and where a PHP directive may or may not be set. This is explained here: http://www.php.net/manual/en/ini.list.php A virtual host may be configured to use a local php.ini file in place of … Continue reading →

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MySQL Replication Tools

Posted on November 19, 2013 by vicki

If replication stops and the slave status shows: Last_Errno: 1580 Last_Error: Error ‘You cannot ‘ALTER’ a log table if logging is enabled’ on query. Default database: ‘mysql’. You need to skip over a bad query as follows: mysql> SET GLOBAL … Continue reading →

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