Technology Insights

Virtualization on any platform with VirtualBox

In my day to day work, I need to have access to multiple operating systems in order to test various things.  Unfortunatly running multiple desktops gets warm and traveling with multiple laptops gets cumbersome.  I serached out and tried various virtualization technologies that would address my problems.  In the end, after testing VMWare, various Xen ( Xen was purchased by Citrix ) incarnations, I finally settled on VirtualBox. Virtualbox was created and sold by Innotek. Sun eventually bought innotek in February of this year.  VirtualBox allows you to install the software on a base system (called the “host”) and within the software you create multiple virtual computers with different operating systems (called “guests”).

Technology Errors

STARTTLS: read error=generic SSL error

When receiving this error you are either having a STARTTLS problem or there is a chance that it is a bug in sendmail and you just need to supply a patch to sendmail. First to resolve the issue follow the below steps.

1. Stop sendmail: /etc/init.d/sendmail stop
2. Make sure the PID’s all stopped: ps -ef | grep sendmail
3. If not kill the stuck process ID’s: kill -9
4. Also check the PID’s from the maillog where you originally saw the error and make sure those are not running.
5. Start sendmail: /etc/init.d/sendmail start

Technology Insights

How to Configure yum-updatesd to Notify By Email

On most new CentOS server installs yum-updatesd is installed by default and by default it sends notifications to the dbus. You do however have the option to configure it to send updates via email or to syslog. If you do decide to have updates sent via email then you will need to add a couple more configuration options to /etc/yum/yum-updatesd.conf which are email_to and email_from. Listed at the bottom of this post is the default configuration file followed by a yum-updatesd.conf file that will send email notifications of new files.

Another thing to watch out for is yum-updatesd locking your ability to update files via yum. While it is checking to see if there are new packages available it puts a lock on using yum so if you run into this problem you either want to remove yum-updatesd or set its configuration to not check once every hour. I changes my default to 10800 seconds or 3 hours.