The following is a list of limitations which have been introduced to the usage of PHP within the uCoz service. Please understand these are to improve system stability and security.

• The following functions are not permitted to be used at any time:
  • system calls (proc_open, proc_terminate, shell_exec, system etc)
  • low-leveled functions of file system work (dio_fcntl, dio_open, dio_read, dio_seek etc)
  • posix functions
  • shared memory functions
  • MySQL functions (mysql_stat, mysql_pconnect)
  
  
• The maximum size of scripts available to be uploaded to the PHP server is 10Mb.
• The available disk space for an entire PHP account is 200Mb.
• The maximum number of files which can be stored on 1 PHP directory is 200.
• The maximum number of files which can be stored on the entire PHP account is 10 000.
• The maximum execution time for a single PHP script is 25 seconds.

The limitations on disk space and the maximum of files available to be stored on the server can can be increased, but only when necessary and for a rational application. To do this you will need to write to technical support via the control panel.

Any further questions you have regarding the limitations applied to PHP usage can be asked here in this thread.