At my current work place, we use Puppet to manage desktop machines. Recently, I need to prepare an new image based on Ubuntu 14.04 LTS. To prepare an image, in brief, first thing is to install a fresh Ubuntu on a machine, compile and package lots of applications, and make change to configuration such as look and feels, etc. As mentioned earlier, I use Puppet to manage machine, so I store all customed configuration on the Puppet server. ...
So you drop a script in /etc/cron.daily. How to check if that script does what it is expected to do without having to wait, in this case, a day? Here is how: # run-parts -v /etc/cron.daily Reference: http://stackoverflow.com/questions/4984725/how-to-test-cron-job
I need to install pg 0.17.1 gem on a server running CentOS. This is the error message I saw: # gem install pg -v '0.17.1' Building native extensions. This could take a while... ERROR: Error installing pg: ERROR: Failed to build gem native extension. /usr/bin/ruby extconf.rb checking for pg_config... no No pg_config... trying anyway. If building fails, please try again with --with-pg-config=/path/to/pg_config checking for libpq-fe.h... no Can't find the 'libpq-fe.h header *** extconf.rb failed *** Could not create Makefile due to some reason, probably lack of necessary libraries and/or headers. Check the mkmf.log file for more details. You may need configuration options. ... First thing came to my mind was I must have forgotten to install the -dev package. ...
Ever since Oracle took the ownership of MySQL, I’ve been leaning more and more toward PostgreSQL, or other NoSQL database like MongoDB. Also, I’m not completely new to PostgreSQL, but the fact that I only have to touch it once in awhile, makes me feel PostgreSQL is so hard to use and missing the goold-oldie MySQL. Anyway, this is the issue I had: # su - postgres -bash-4.1$ psql -l List of databases Name | Owner | Encoding | Collate | Ctype | Access privileges -------------+----------+----------+-------------+-------------+----------------------- postgres | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | postgres-db | postgres | UTF8 | en_US.UTF8 | en_US.UTF8 | puppetdb | puppetdb | UTF8 | en_US.UTF8 | en_US.UTF8 | template0 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres template1 | postgres | UTF8 | en_US.UTF-8 | en_US.UTF-8 | =c/postgres + | | | | | postgres=CTc/postgres (5 rows) -bash-4.1$ psql -d puppetdb -U puppetdb --password Password for user puppetdb: psql: FATAL: Peer authentication failed for user "puppetdb" To fix it, we need to modify pg_hba.conf, which is located in the /var/lib/pgsql/9.3/data/ directory on my system. ...
First find out what states your system is supported: $ cat /sys/power/state mem disk To suspend to ram: # echo -n mem > /sys/power/state To hibernate: # echo -n disk > /sys/power/state Ref: http://askubuntu.com/questions/1792/how-can-i-suspend-hibernate-from-command-line