If you want to install DokuWiki on rented webspace this document has some useful tips.
Have a look at the Screencast for this type of installation.
You should first follow the basic instructions, eg:
If you fixed any permission problems through chmod, it is most probably because the webserver runs as different user than the account you use to upload your files. If the group differs as well then the webserver (which runs the DokuWiki application) will create files you will not be able to delete as your normal (FTP) user. To avoid this you need to releax permissions setting through the fmode and dmode settings.
For fixing files with already wrong permissions you can either ask your hosting support for help or use the fixperms.php script.
For changing a whole directory with subfolders, FileZilla v. 3 (In December 2006 it is still Beta, but works fine for this task) supports now 'recursive settings' of permissions for directories as well as files, or only directories or only files.
Some hosting providers do not provide a working sendmail on their servers. Instead, a separate machine runs SMTP and requires authentication. In this scenario, DokuWiki's email features, including allowing new users to register and receive a password, will not work.
There is an unofficial, unsupported patch to versions 2006-11-06 and 2007-06-26b that allows DokuWiki to be configured to use an external SMTP host, with or without authentication. Information is available here.
When following the ordinary install procedure on a hosted Strato 'Powerweb A' server, you might encounter problems that pages can be created, and everything regarding authentication will produce a ‘500 Internal Server Error’, despite permissions set as suggested in the screencast. Circumventing the authentication problem by manually adding users in the users.auth.php file does not seem to improve. (Preventing the notice user doesn’t exist). Even adding the authentication with an md5 hash manually will produce this error. The solution which another user presented was the following:
change the “passcrypt” option in the local.php from “smd5” to “md5”
The configuration of php is very restrictive here, and there's an unoffical patch for DokuWiki to work correctly. The forum thread where you can download the patch can be found here.