I tried to install Piwik 1.11.1 on my server. The first time I go to the installation page, I get the welcome screen then when I click on Next, I get a blank screen.
I tracked down the problem to the function checkIfFileSystemIsNFS() in the core/Piwik.php file.
The problem is that when the line :
@exec($command, $output, $returnCode); is executed, the script hangs.
Having a look at my log files (/var/log/messages), I discovered that this function is blacklisted :
ALERT - function within blacklist called: exec()
With further investigations, I found that the cause is suhosin blacklist (you can get the blacklisted functions with phpinfo() and search the line suhosin.executor.func.blacklist).
For security reasons, I don’t want to remove this function from the list. So I just commented this line and added return false; after (because I kwon the my filesystem is not NFS.
Now, I get a warning in the optional requirements during step 2 of the installation, but It’s not important because I could finish the installation normally.