1. 建立一个大型档案

# dd if=/dev/zero of=/home/loopdev
bs=1M count=512

if : input file
/dev/zero是会一直输出0的装置

of : output file

bs是每个block大小

count是总共有多少个bs

屏幕输出：

512+0 records in
//读入512笔资料

512+0 records out //输出512笔数据

536870912 bytes (537 MB) copied, 6.45734 s, 83.1 MB/s

2.格式化

# mkfs -t ext4 /home/loopdev

使用ext4文件系统格式

屏幕输出：

mke2fs 1.41.12 (17-May-2010)

/home/loopdev is not a block special device.

Proceed anyway? (y,n) y //由于不是正常的装置，所以会提示，选择y，按Enter继续

屏幕输出：

Filesystem label=

OS type: Linux

Block size=4096 (log=2)

Fragment size=4096 (log=2)

Stride=0 blocks, Stripe width=0 blocks

32768 inodes, 131072 blocks

6553 blocks (5.00%) reserved for the super user

First data block=0

Maximum filesystem blocks=134217728

4 block groups

32768 blocks per group, 32768 fragments per group

8192 inodes per group

Superblock backups stored on blocks:

32768, 98304

Writing inode tables: done

Creating journal (4096 blocks): done

Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 36 mounts or

180 days, whichever comes first.  Use tune2fs -c or -i to override.

3.挂载

# mount -o loop /home/loopdev /root/myloopdev/

将该档案挂载到/root/myloopdev/下

查看下磁盘空间情况

# df

屏幕输出：

Filesystem           1K-blocks      Used Available Use% Mounted on

/dev/xvda1            20641404   6202512  13390368  32% /

tmpfs                   960472         0    960472   0% /dev/shm

/home/loopdev           516040     16780    473048   4% /root/myloopdev

成功！