For those of you following my adventures with the WordPress WXR/RSS export feature (here, here, here and here), I finally figured out why the resulting file was truncated and only contained posts up to October last year. It’s so simple I’m kicking myself for not figuring it out sooner: PHP on my webhost was configured to only allow a maximum file size of 4MiB.
As I’ve said before I’m not a PHP guy so I had to do a bit of digging, but it turns out the most reliable way to increase allowed file sizes if you don’t have access to your php.ini file (usually this is the case) is to add the following line to your root
php_value memory_limit 32M
You might have to do some trial and error to find a size value that works. If in doubt, contact your webhost.
I think the people at WordPress ought to include a simple warning on the Export page of people’s blogs informing them of the file size limitation on their web servers, or barring that issue an error if it runs out of space with a link to a page explaining how to increase available file sizes instead of cheerfully and misleadingly informing users the export is finished. I imagine there are plenty of people who’ve been caught out by this, some of whom I’m sure aren’t web developers and wouldn’t know where to even start looking to solve this.