Could someone help me with this problem please........

I have these values set on my parameter:


sga_max_size = 128M
db_cache_size = 20M
shared_pool_size = 30M
log_buffer = 524288
# large_pool_size = 32M
# java_pool_size = 20971520

Everytime I have SGA_MAX_TIME in my parameter, I got the following message:

ORA-00445: background process "PMON" did not start after 120 seconds


If I comment out the SGA_MAX_SIZE, I was able to create my database without having any problem.

I read the docs dynamic SGA but I am not quite clear about the values and all,

Could some senior or maybe Jeff or Julian help me to understand better????

thanks