1.查看内存
[root@greymouster ~]# free -m #以M查内容 total used free shared buffers cached Mem: 1006 163 843 0 22 72 -/+ buffers/cache: 68 938 Swap: 2047 0 2047 [root@greymouster ~]# free total used free shared buffers cached Mem: 1030492 166972 863520 248 23160 73992 -/+ buffers/cache: 69820 960672 Swap: 2097148 0 2097148 [root@greymouster ~]#
提示：1）linux系统的特性是将系统不用的物理内存缓存起来，因此843 不是系统的真实内存
2) 系统真正系统内存是938M
3）buffers 为写入缓冲区，sync 将buffer缓冲区数据写入磁盘，cache 为读出缓存
查看磁盘：
[root@greymouster ~]# fdisk -l Disk /dev/sda: 21.5 GB, 21474836480 bytes 255 heads, 63 sectors/track, 2610 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000e5001 Device Boot Start End Blocks Id System /dev/sda1 * 1 26 204800 83 Linux Partition 1 does not end on cylinder boundary. /dev/sda2 26 287 2097152 82 Linux swap / Solaris Partition 2 does not end on cylinder boundary. /dev/sda3 287 2611 18668544 83 Linux
[root@greymouster ~]# echo $((2610*255*512*63))
21467980800
磁盘大小=磁道数*磁头数*512字节*扇区数
= 2610 * 255 * 512 *63