I’ve got an Ubuntu 10.10 install that I’ve configured with LAMP and installed WordPress on top of. Pretty much everything works fine on it apart from image thumbnails not being generated on upload. At first I tracked this down to it missing php-gd but I’ve installed that module (via apt-get install php5-gd and then restarting Apache) which seems to make WordPress think it’s doing the resize as all the options are no longer greyed out but looking in the uploads directory I can see that no other files were generated.
Running php -m shows GD as a module and it also shows up in phpinfo(). Nearly every article I’ve read on this particular issue says its resolved by installing GD but that has not worked in my case. There’s nothing in the PHP or Apache error logs that give me anything to go on so I’m not quite sure to do. It’s a VPS that I have full root access to so if there’s any command you need me to run that won’t be a problem.
Make sure you also have php5-imagick installed, not just GD