i tried installing but got the following error after pressing the 'build the site' button:

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Warning: tempnam() [function.tempnam]: open_basedir restriction in effect. File(/tmp) is not within the allowed path(s): (/var/www/htdocs/mysite/:/tmp/:/var/tmp/:/var/lib/php5) in /var/www/htdocs/mysite/public/ss/install.php on line 338

Warning: unlink() [function.unlink]: No such file or directory in /var/www/htdocs/mysite/public/ss/install.php on line 339

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /var/www/htdocs/mysite/public/ss/install.php:338) in /var/www/htdocs/mysite/public/ss/install.php on line 516

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /var/www/htdocs/mysite/public/ss/install.php:338) in /var/www/htdocs/mysite/public/ss/install.php on line 516
Installing SilverStripe...

I am now running through the installation steps (this should take about 30 seconds)

If you receive a fatal error, refresh this page to continue the installation
# Creating 'mysite/_config.php'...
# Creating '.htaccess' file...
# Building database schema...
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after this appeared nothing happened. going back to the index gave me this:

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Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [no address given] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

look up open_basedir restriction in effect on google and you'll find a lot to solve your problem.

I think /tmp is the folder SS use to build its "cache", you may be able to resolve the problem if you create a folder in your httpd root directory called "silverstripe-cache" so that it'll use that directory instead.

looks as if you might not have access to the /tmp directory.

can the following also be attributed to the open_basedir restriction?:

Warning: unlink() [function.unlink]: No such file or directory in /var/www/htdocs/mysite/public/ss/install.php on line 339