5 Common Drupal Mistakes You Can Avoid

This is a list of the most common mistakes I have encountered in my daily Drupal work. It can seem like obvious things for the daily Drupal hacker, but are nevertheless commonly seen when working on projects someone else has started or maintained.

1) Installing modules part I: In the wrong place

One of the most common, if not the most common mistake is to place contributed modules in the modules folder which is in the root of the installation directory. This directory should only contain core modules, which are modules that is included in Drupal's installation package.

Any additional modules downloaded from drupal.org/project/modules or any other site, and also modules you create yourself, should be placed in the /sites/all/modules folder. This folder does not exist by default so it needs to be created.

Folder structure for Drupal 6.

/drupal-root
  /includes
  /misc
  /modules      <-- place for core modules
  /profiles
  /scripts
  /sites
    /all
      /modules  <-- place for contributed modules
      /themes

2) Installing themes in the wrong place

If you read number 1 above, this one is almost self explanatory. Just like contributed modules should be located in /sites/all/modules directory, contributed themes should be uploaded to the /sites/all/themes directory. Neither of these folders exists by default and need to be created.

3) Not making regular backups

Why do you have insurance for you car? That's right, in case something goes wrong. Making backups of your Drupal installation is a life-saver if something goes wrong. Solution: Take a look at the Backup & Migrate module that helps making this task really easy. All though it's a good module I would suggest to make manual backups of the complete installation, or at least your /sites directory, and also make an export of your database once in a while.

4) Installing modules part II: ... like there was no tomorrow

It's true that the default Drupal installation is limited in functions, but each module installed take its part of the performance. The more modules, the slower things will go. Read up on what the modules do and weigh that against what you need and what you don't need. I encourage developers to install modules, but always read the issue questions and documentation before. Ask yourself if there is no other way to manage what you want to do. You can do a lot with some of the most popular modules like CCK and Views. There are also a lot of code snippets and "mini modules" that could do what you wish. In most cases, it's just to copy and paste. Another reason to read the documentation and issue que is because some modules are incompatible with each other and can break your site if you have bad luck.

5) Installing modules part III: Folder structure

When downloading a module you will probably get a .rar archive that has a name like cck-6.x-2.3.tar.gz or something similar. The "6.x" part is the Drupal version number, and the "2.3" is the module version number. When extracting this archive you will have a folder named cck-6.x-2.3 as well, and inside that folder there will be another folder called just cck. It's the folder named just "cck" that should be uploaded in the modules directory (mentioned in no. 1), and not the cck-6.x-2.3 folder.

Seen any other common mistakes? Leave a comment.