Linux Tips and Tricks, Part 1

LinuxI’m going to assume that you know how to do some basic stuff in Linux. In other words, if you don’t know what a command line is, or how to traverse directories, this might not help you much.

I should also note that my preferred flavor of Linux is Ubuntu. These commands will work on Ubuntu, but I can’t make any guarantees for other distributions. Best to just try them out and see what happens!

Without further ado, here are some of the top linux tips and tricks that I have gathered over the years…

Read more…

The 3GB Barrier: Why you want a 64-bit OS

64-bit = GoodI’m sure you’ve all heard some hype about 64-bit this and 64-bit that. The thing I read the most is that a 64-bit operating system or piece of software is automagically twice as fast as a 32-bit one. Not so. Worse yet, some operating system vendors market their product as having an “advanced 64-bit architecture”, when the truth of the matter is that their OS is not fully 64-bit.

In any case, most people today are using a 32-bit operating system, but a surprising number have already switched to a 64-bit OS. Or in some cases, a quasi-64-bit OS…

There is one true reason though why you will actually want to switch to a 64-bit OS in the near future: the infamous 3GB barrier. Just what the heck is this mystical barrier, and why should you care?

Read more…

Making Strong Passwords – and Keeping them Safe

lock-and-keyEveryone is totally crazy about security these days – especially computer security. We’ve all got antivirus software, a firewall, spyware scanners, and god knows what else loaded up on our PCs to protect ourselves from the “evils” of a networked world.

Some of us choose to use certain operating systems that we believe are inherently secure, while the reality is quite different. I remember hearing all about how “ultra-secure” OS X Tiger was in comparison to Windows XP. I know a lot of people who believed this, and who even went out of their way to harp on XP and how insecure it was. Well, there have been numerous updates for Tiger and Leopard that were sent out from Apple HQ. Guess what? There were scores of security vulnerabilities in OS X. What really might shock you is that the vulnerabilities in OS X read like a list of XP security holes (see here and here and here). That’s right, just because Apple tells you OS X is safer doesn’t mean that it’s actually true! Go figure!

Of course, there’s also Linux. In some respects, Linux is safer. In others, it’s no different than XP and OS X. Personally, I prefer Ubuntu and Vista at the moment. But the bottom line is that when it comes to security, it’s up to you to keep your data safe. The first and best way you can do that is to create and use strong passwords!

Read more…

Optimize Your Caching Scheme to Eliminate “Too many links” Errors on Linux

Say you have an application running on a Linux server using the ext2 or ext3 file systems. You set up a caching scheme in your application to store files like so:

/cache/stamps/1/main_content.cache
/cache/stamps/1/comments.cache

/cache/stamps/2/main_content.cache
/cache/stamps/2/comments.cache

/cache/stamps/3/main_content.cache
/cache/stamps/3/comments.cache
...

Eventually, you’re going to run into a problem: Your caching will stop working since your application won’t be able to write to the “stamps” directory any more. Instead, you’ll get an error message like this:

Couldn't create cache directory: /stamps/41134/main_content (Too many links - /var/www/your-app/tmp/cache/stamps/41134)

At that point, you’ll try to search for “too many links”, and probably you won’t find much information that is actually comprehensible to normal human beings. Fortunately, it really is quite simple to repair once you understand what’s going on.

Read more…