quotaon
quotaon功能说明：开启磁盘空间限制。
语 法：quotaon [-aguv][文件系统...]
补充说明：执行quotaon指令可开启用户和群组的才磅秒年空间限制，各分区的文件系统根目录必须有quota.user和quota.group配置文件。
参 数：
-a 开启在/ect/fstab文件里，有加入quota设置的分区的空间限制。
-g 开启群组的磁盘空间限制。
-u 开启用户的磁盘空间限制。
-v 显示指令指令执行过程。
quotaon
quotaon [options] [filesystems]
System administration command. Turn on enforcement of filesystem quotas. To work, the filesystems must have a gpquota, quota, or usrquota option listed in the /etc/fstab file. On most filesystems, user and group quota files must also exist. XFS filesystems store quota information as metadata instead of as files. Use edquota or setquota to create the appropriate quota information.
Options
Turn on quotas for all autoloading filesystems in /etc/fstab that support them.
Invoke quotaoff instead of quotaon.
Turn group quotas on.
Print current quota status, then exit.
Turn user quotas on.
Print a message for each filesystem affected by the command.