In preparation for WordPress Backup Week, I needed to backup my site so I would know 1) how to do it, and 2) how to help others. And I learned a LOT!
First of all, the process of backing up WordPress is a two fold step. You need to backup your database and your site. The instructions at WordPress Backups will take you through both processes.
Second, the WordPress Backup Plugin by Skippy and Ringmaster is great. You can find it at http://redalt.com/downloads/
It is very simple and easy to use and you can have the backups saved to the server for later retrieval, downloaded immediately, or emailed to you. WOW!
BUT, this is where the lessons come in. Pay close attention or you may repeat my mistakes.
I was very impressed with the plugin. It automatically chooses all of the default tables in the database created during the installation, and then optionally allows you to choose other tables in your database, usually created and used by various plugins you may be running on your site. I clicked them all to backup.
Two hours later, the backup was still running and I got really nervous.
What I didn't know is that there is a ton of stuff in those tables that I don't need to backup, but no one told me.
Now you are being told!
Comment spam and site statistics are stored in some of those tables. This is information that collects until it's deleted, by the plugin or by you, whichever comes first. My site statistics table was 32 megabytes in size! My posts and core WordPress tables came to only 8 megabytes, so I was backing up months of statistics that I didn't really need. If you aren't running Spam Karma 2 or another comment spam plugin that doesn't automatically deletes comment spam from your database, who knows how big that table could be.
It is actually easy to empty the tables before you back things up, if you need to. The article on Emptying a Database Table in the Codex should be used with great care, but it can empty tables from your database if you need to clean them out.
And when backing up manually or with the Backup Plugin, be very careful with what you choose to backup from those optional tables!
Part Two of the backup process is backing up your site's files. After all, you worked really hard on that Theme, it'd be a shame to lose it or have to do all that work over again. Don't forget about those useful plugins! And the images and graphics you painstakingly added to your photoblog, gallery, and posts. Those need saving and backing up, too.
Again, I was caught off guard by the sheer size of the junk that had collected.
There are a lot of plugins I've added over the months that were great ideas but just didn't work out for me in the end. Yet they stayed there, gathering dust and eating up space on my server. Sure, not much, but when I'm backing up over the Internet, it adds to the bandwidth and time to download the backup.
I printed the list of plugins from my Admin Plugins List and using an FTP program, went though the folder with my plugins and deleted the ones I didn't have activated. This cut the size of my Plugins folder by more than half.
I deleted Themes I didn't use any more, cutting down the size of the theme folder by 75%. I test drove a lot of Themes before creating my own.
I printed out the instructions for restoring the database from the Codex and folded and taped them to my CD case for the backup. Just in case.
In the future, now that my site has been "pruned to size", backups will be faster and easier.
Now, GO BACKUP!