小妙招使用sysctl hw.realmem查看实际物理内存@FreeBSD

使用sysctl hw.realmem查看实际物理内存：The realmem value is memory before the kernel and modules are loaded, whereas

hw.physmem is what is left after they were loaded.

使用hw.physmem查看去掉kernel和模块调用后剩余的内存

sysctl hw.ncpu是机器的cpu核数

比如这样一台机器：

fb12:/root@[16:22] # sysctl hw.physmem
hw.physmem: 8427704320
fb12:/root@[16:23] # sysctl hw.realmem
hw.realmem: 8589934592
fb12:/root@[16:23] # sysctl hw.ncpu
hw.ncpu: 4

物理内存是8589934592

这是8G的内存，可以在HY中计算，2的33次方就是8589934592

=> (** 2 33)

8589934592