??? ?? [dbtest@test55 ~]$ free
???????????? total?????? used?????? free???? shared??? buffers???? cached
??? ??? ??? Mem:?????? 2074840??? 1275356???? 799484????????? 0???? 168264???? 864196
??? ??? ??? -/+ buffers/cache:???? 242896??? 1831944
??? ??? ??? Swap:????? 2096472????????? 0??? 2096472

??? ?? 1、创建一个8M的空文件：
??? ?? [root@test55 ~]# dd?? if=/dev/zero?? of=swap1?? bs=1024?? count=8192
??? ??? 8192+0 records in
??? ??? 8192+0 records out
??? ??
??? ?? 2、创建交换分区：
??? ?? [root@test55 ~]# /sbin/mkswap?? swap1?? 8192
??? ??? Setting up swapspace version 1, size = 8384 kB

??? ?? 3、打开交换分区：
??? ?? [root@test55 ~]# /sbin/swapon?? swap1?

?????? 4、查看交换分区大小，发现已经增加了8M：
??? ?? [root@test55 ~]# free
???????????? total?????? used?????? free???? shared??? buffers???? cached
??? ??? ??? Mem:?????? 2074840??? 1330460???? 744380????????? 0???? 214796???? 872264
??? ??? ??? -/+ buffers/cache:???? 243400??? 1831440
??? ??? ??? Swap:????? 2104656????????? 0??? 2104656

????? 5、如果要去掉这个新的交换分区，用如下命令：
??? ?? [root@test55 ~]# /sbin/swapoff?? swap1?
??? ??? [root@test55 ~]# free
???????????? total?????? used?????? free???? shared??? buffers???? cached
??? ??? ??? Mem:?????? 2074840??? 1330524???? 744316????????? 0???? 214812???? 872248
??? ??? ??? -/+ buffers/cache:???? 243464??? 1831376
??? ??? ??? Swap:????? 2096472????????? 0??? 2096472

??? ??? ??? 显然，交换分区缩小了。