Cron on Michael’s Domain

Why some scripts in the cron.hourly directory do not become executed

Sat, 09 Jun 2007 00:00:00 +0000

Because I have a very basic mp3 player that cannot play back anything but ISO-standard mp3s, I often need to re-encode podcasts which my podcast-catcher downloads (I use Amarok). I created bash scripts to re-encode all downloaded mp3s and to generate a new RSS feed based on the directory content where the re-encoded mp3s get stored. However, the scripts did not get executed every hour and the reason was their naming (“podacst_downsampling.sh”). There are quite strict rules how the names have to look like (which I don’t remember), but if you use only a-z characters you should be always fine. After renaming to “podcastdownsampling” everything worked fine.

Editing the crontab

Thu, 24 May 2007 00:00:00 +0000

We have a shared directory (/home/shared) on our computer and a usergroup called “shared”. The purpose is that we put things there that should be accessible (including writable) to several users of the system. If one user puts a file there, it can be read by others but not e.g. deleted. In order to fix this, we edited the crontab to execute every 5 minutes the following two commands: chgrp -R shared /home/sharedchmod -R 744 /home/sharedIn order to do this we edited (as root of course) the /etc/crontab file by adding the line: */5 * * * * root run-parts /etc/cron.minutelyThis means execution every 5 minutes, every hour, every day, every month, every weekday the script run-parts should be executed as root taking all scripts from the /etc/cron.minutely as argument (we created this directory newly in addition to the already existing /etc/cron.hourly, etc.). We restarted crond (the crontab deamon) via the GUI (under RedHat 9 Menu-System Settings-Server Settings-Services).

How to backup mysql databases (mysqlhotcopy, mysqldump)

Sat, 16 Dec 2006 00:00:00 +0000

There are different possibilities. If you have access to the machine where mysql is running, you should use:mysqlhotcopy On our RedHat 8 server you just type:/usr/bin/mysqlhotcopy --user=root --password=sdjksjd journal /path/to/backup/directory Alternatively:/usr/local/mysql/bin/mysqldump --user=username -p phpgedview >phpgedview The path of the command is specific for the mysql install on a MacOS X machine.If you want to back up from another machine you can use the mysqldump command: mysqldump --host=hostname_or_ipaddress --user=username -p phpgedview >phpgedview This example backs up the database phpgedview which is on the machine hostname_or_ipaddress.The actual database files are in subdirectories in /var/lib/mysql in case you don’t remember their names.To automatically backup a database via the network you can put a file with the following content to the /etc/cron.hourly directory:!/bin/sh mysqldump --host=hostname_or_ipaddress --user=USER -pPASSWORD journal >mysqldump_journal This would create every hour a fresh backupfile called mysqldump_journal in the /etc/cron.hourly directory.