Installing VirtualBox Guest Additions from a Linux Host

Installing VirtualBox Guest Additions on a Linux host is a straight-forward task which can make life much easier on a guest operating systems, or OS. The Guest Additions install is the equivalent of installing VMWare Tools on a VMWare host (onto a VMWare guest OS). I’ll discuss the enhancements of installing the VirtualBox Guest Additions, and will run you through the installation process. Continue reading Installing VirtualBox Guest Additions from a Linux Host

Compiling Duplicity on CentOS 5.x

Duplicity, an encrypted backup utility that uses the rsync algorithm, is becoming quite useful for my day to day backups. I’ve written several backup scripts using rsync, gzip, and other useful backup schemes. Heck, I’ve even written my own backup subroutines that create a backup structure based of the current date. So, trust me, I usually never change my ways, unless it’s something that really intrigues me. Continue reading Compiling Duplicity on CentOS 5.x

Splunk Free: .htaccess Protection using Apache

You ever hear of Splunk? Splunk enables you to search and navigate all your logs and IT data in real time; logs, configurations, messages, traps and alerts, scripts and metrics. It’s an awesome tool to make it easier to monitor and watch your log files. Unfortunately, Splunk is expensive. How expensive? Try $5000 a year, for the cheapest license. Here’s the main problem; the free version of Splunk does not come with any user authentication, not even Admin authentication. This means that anyone can access your Admin area of Splunk, and can see any log files you have and can even set up new Splunks (log file watches). Let’s fix this!

I would have thought that a standard feature of Splunk would be at least Admin user authentication, but you can only get that with the professional version of Splunk. You have 30 days of the Professional version of Splunk, and then you must purchase the license after that. So, most individuals that just want to manage their log files remotely via the web, cannot afford and should not even purchase a Professional license, so the Free version is perfect. The lack of authentication kind of makes you turn your nose to Splunk, as this posses a security issue. Note one thing, when I say authentication, I mean username and password. You literally can access all admin features, including license information, just by going to the web address (which is usually a domain name on the default port 8000, e.g. http://domain.com:8000). This is totally rediculous. We can get around this by running a proxy within Apache and secure the subdomain (http://splunk.example.com/) with a .htaccess file. Continue reading Splunk Free: .htaccess Protection using Apache

Clearing (but not deleting) log files

Sometimes, as a Systems Administrator, or SysAdmin, there are times we need to clear out the log files, without actually deleting them. As a smart Sys Admin, you normally wouldn’t need to do this, but as I am currently involved in supporting customers and their Linux machines, I run into some pretty neat stuff (neat as in special). I’ve had a few issues where someone actually runs out of disk space on / (root filesystem) due to the /var/log directory being full.

First off, you might run the df command only to realize that, maybe, you have used 97% of the partition up, in this case / (root filesystem). More times than not, this is usually due to your /var/log directory. Make sure though, I’m presuming that you already know that your /var/log directory is full. To find out what is taking up the most space (you should already know why, and thus you are viewing this possibly because you are having issues with a full filesystem), you would need to run the df command. Continue reading Clearing (but not deleting) log files

Curing ‘Symbolic link not allowed’ (Apache 2.0)

Awhile back when trying to add a directory to Apache on my Ubuntu 6.06 LTS server, I ran into some issues. These issues, of course were the infamous 403 “Forbidden” error that your web barfs up when you try to access a server that is not publicly viewable, because of permission issues. I’m going to give you my scenario and explain how you can fix this issue, so that you don’t have to go through an hour of throwing your hands up in disgust. Continue reading Curing ‘Symbolic link not allowed’ (Apache 2.0)