Dd is a tool that is often used in computer forensics because it is extremly low level and effecient at creating exact duplicates of hard drives. For this reason it is often the tool for which all other tools are compared to. But is it useful for us regular Joes?. Can we use dd to create digital copies of our hard drives for backup reasons? Yes we can, and I actually find that it is easier to use than commercially available solutions Read more »

Fork bombs are basically a never ending loop. They open a processes that opens other processes that open even more processes exponentially. Causing any computer to lock up within a matter of seconds. Although they have to be ran from a logged in user they are still a threat. Users can unintentionally cause a complete lockup of a production server. Read more »

SSH by default is very strong. It has protection against various hacks and known vulnerabilities. For instance SSH has a password retry wait time of five seconds. This makes the time for brute force attacking an SSH server very long and probably not effective. However, sometimes script kiddies will fork their hacking program making multiple processes of the brute force attack. Sometimes they are able to fork it off upwards of 1000 attempts every 5 seconds. This drastically minimizes the time to crack short passwords. Read more »

Recently I accidently changed the permissions of one of my files and I didn’t know what the correct permissions were suppose to be. I did know that the other files in the same directory were the correct permission. Using the ls -l command. I was able to see that the permission was set as, -rw-r–r–. Great, I now know the correct permission; however, I usually use the binary syntax for chmod and I am not familiar with the other method. Read more »

Getting fetchmail to work in Linux or FreeBSD has always been difficult for me. The SSL certificates always seem to be a pain to configure. It has been particularly difficult to get fetchmail with Gmail working on FreeBSD since there are no complete guides written for FreeBSD. Read more »

By default FreeBSD does not come with a screen saver for console. It also does not come configured with a power saving mode. If you don’t use the console for some time I prefer to save energy and have my monitor turn off when it is not in use. Here is how you can install a screen saver for your FreeBSD 7.0 system. Read more »

If you are using a Linux system and want to schedule a task to run in the future you will probably need to know cron. Cron is much like Window’s Scheduled Tasks. The only difference is that cron is conifgured by a simple text file. Although, that text file to the untrained looks very complicated. Many people rely cron task generators to do the work but I hope that after this guide you will be able to make your own tasks without the use of a generator. Read more »

If you have heard about Linux or currently using it you are probably aware that it was derived from Unix. Linux is not the only variant derived from Unix. There has been a number of Unix variants one of which is, FreeBSD.

Since FreeBSD recently announced a new release I thought I would give it a try. When they released FreeBSD 7.0 they had claimed that it performed at least 15% faster than the latest Linux kernel. For such as substantial increase in performance I just had to give it a try. Here is how it went. Read more »