since 8 core license, there'll be 9 lshttpd processes running.
assume each process consume 200MB memory, the total memory usage may be reported as 200MB x 9 = 1.8G. but needn't worry much, since within the 200MB memory, many of them are shared. the memory usage reported by "top" is same case. using "free -m" can check the actually available memory.
using "pmap -x <pid of an process>" can display the memory map of the process.
however I have no clue about why graceful restart not working well.