In case you get this error message when you upload an image:
“Failed to write file to disk”
Check this solution:
This message is related to WordPress files that connect to uploads.
Our recommendations are:
– Check that upload folder permissions are 777 or 755 – help http://codex.wordpress.org/Changing_File_Permissions
– Check with your hosting to see if your disk space is not full and you need to upgrade hosting