查看“Linux 磁盘配额管理”的源代码

==文件系统配额设置==
==配额的基本概念==
磁盘配额是一种磁盘空间的管理机制。使用磁盘配额可限制用户或某个组在某个特定文件系统中所能使用的最大空间。

根据配额特性的不同，可将配额分为硬配额和软配额。硬配额是用户和组可使用空间的最大值。软配额允许一定时间内被超过。
===编辑/etc/fstab文件===
用vi编辑器打开/etc/fstab文件，对/home所在行进行修改，增加命令选项userquota 和grpquota

 <nowiki>#
# /etc/fstab
# Created by anaconda on Thu Jun 28 04:40:29 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=7867ecde-68a9-437f-b68c-1b8e16a53346 /                       ext4    defaults        1 1
UUID=eec138a9-9e94-4757-8a7f-fc3ccb56c153 /home                   ext4    defaults,userquota,grpquota        1 2
UUID=4657ef5a-8967-41c0-8818-04564bf6a4f0 swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/dev/sdb1               /mnt/hello              ext4    defaults</nowiki>  

===重启系统===
重启系统可使系统读取/etc/fstab文件的内容，重新挂载

===创建配额文件===
执行命令quotacheck命令

quotacheck命令的基本功能是检查每个文件系统、建立目前硬盘使用率列表以及检查每个文件系统的空间限制。

[root@localhost ~]# quotacheck -avgu

 <nowiki>quotacheck: Your kernel probably supports journaled quota but you are not using it. Consider switching to journaled quota to avoid running quotacheck after an unclean shutdown.
quotacheck: Scanning /dev/sda3 [/home] done
quotacheck: Cannot stat old user quota file: No such file or directory
quotacheck: Cannot stat old group quota file: No such file or directory
quotacheck: Cannot stat old user quota file: No such file or directory
quotacheck: Cannot stat old group quota file: No such file or directory
quotacheck: Checked 7 directories and 3 files
quotacheck: Old file not found.
quotacheck: Old file not found.</nowiki>

查看/home目录

 <nowiki>root@localhost ~]# cd /home
[root@localhost home]# ls
aquota.group  aquota.user  fly  lost+found</nowiki>

===执行edquota命令===
由于aquota.user和aquota.group文件的结构很复杂，无法直接打开进行编辑，因此必须执行edquota命令进行编辑。

edquota -u user1

<nowiki>Disk quotas for user fly (uid 500):
  Filesystem                   blocks       soft       hard     inodes     soft     hard
  /dev/sda3                        32          10240          15360          8        0        0
</nowiki>

执行

[root@localhost home]# edquota -u fly

[root@localhost home]# edquota -u fly

[root@localhost home]# useradd horse

[root@localhost home]# edquota -p fly horse

 <nowiki>[root@localhost home]# groupadd user
[root@localhost home]# gpasswd -a fly user
Adding user fly to group user
[root@localhost home]# gpasswd -a horse  user
Adding user horse to group user
[root@localhost home]# edquota -g user
</nowiki>

===启动配额管理 ===
[root@localhost home]# quotaon -aguv

 <nowiki>/dev/sda3 [/home]: group quotas turned on
/dev/sda3 [/home]: user quotas turned on
</nowiki>

查看配额情况：

 <nowiki>[root@localhost home]#  quota fly
Disk quotas for user fly (uid 500):
     Filesystem  blocks   quota   limit   grace   files   quota   limit   grace
      /dev/sda3      32   10240   15360               8       0       0</nowiki>

===关闭配额管理===

 <nowiki>[root@localhost new]# quotaoff -aguv
/dev/sda3 [/home]: group quotas turned off
/dev/sda3 [/home]: user quotas turned off</nowiki>