I have transferred multiple blogs over the past few months from WordPress to Ghost, and i have compiled a series of lessons learned, along with the fact that every tutorial out there seems to be outdated. I hope this is useful to anyone in the future:
A little side note.
The export option in the wordpress plugin via zip often fails due to wrong php settings.
Most importantly: memory_limit and max_execution_time which should be increased in the php.ini accordingly.
The export process via ghost plugin can take quite some time (several minutes) for websites with alot of content and wordpress by default isn’t configured to let php scripts run for several minutes.
That’s why the export can run into timeouts/errors, because the process gets killed.
when i did my last migration i had 2GB of memory limit for php alone.
256MB could be too little memory for a resource hungry process like exporting all your content.
It really depends on how much total ram your server instance has.
Never claim your total available ram for php so i would recommend setting it to 512MB if available
300seconds should already be enough i think.
You could ssh into your server and then look at your server resources with $htop to see if your instance runs into cpu or memory issues, when trying the plugin.
debug.log in wordpress could also give some info if you have define ( 'WP_DEBUG', true ); in your your wp-config.php
I’ll make adjustments and let you know of the outcome. This should be then a mandatory requirement in the pre-requisites of the official tutorial and the plugin itself.