Note, that in previous versions, the interface was
bool rrd_create ( string $filename , array $options , integer numberOfOptions )(PECL rrd >= 0.9.0)
rrd_create — Creates rrd database file
filenameFilename for newly created rrd file.
optionsOptions for rrd create - list of strings. See man page of rrd create for whole list of options.
Note, that in previous versions, the interface was
bool rrd_create ( string $filename , array $options , integer numberOfOptions )