linux磁盘管理系列一：磁盘配额管理

磁盘管理系列

linux磁盘管理系列一：磁盘配额管理   http://www.cnblogs.com/zhaojiedi1992/p/zhaojiedi_linux_040_quota.html

linux磁盘管理系列二：软RAID的实现  http://www.cnblogs.com/zhaojiedi1992/p/zhaojiedi_linux_041_raid.html

linux磁盘管理系列三：LVM的使用        http://www.cnblogs.com/zhaojiedi1992/p/zhaojiedi_linux_042_lvm.html

1 前言

在linux系统中，由于是多用户、多任务的环境，如果有少数几个用户大量使用磁盘空间，导致其他用户的正常使用，因此需要对各个用户的磁盘空间进行管理和限定。

2 quota的用途

限制某一个用户的最大磁盘配额

3 quota的使用限制

• 仅能针对整个文件系统
• 内核必须支持
• 只对一般用户生效
• 这里提供一个样例，针对样例对quota的配置管理做个描述

4 案例讲解

4.1案例描述

• 创建5个用户user1,user2,user3,user4,user5，密码和用户名相同，初始组为usergrp组。
• 5个用户都可以取得300M的磁盘使用空间，文件数量不限。超过250M,给于提示。
• usergrp这个组内成员最大使用空间1GB。
• 如果有用户超过soft限制，给14天的宽限时间。

4.2 准备磁盘

[root@mail ~]# fdisk -l      #查看磁盘情况
 
Disk /dev/sda: 42.9 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk label type: dos
Disk identifier: 0x000bd275
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *                       Linux
/dev/sda2                    8e  Linux LVM
 
Disk /dev/sdb: 10.7 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
 
Disk /dev/mapper/cl-root: 39.7 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
 
Disk /dev/mapper/cl-swap:  MB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
 
[root@mail ~]# fdisk /dev/sdb     #对sdb这个盘进行分区，这里就分一个区
Welcome to fdisk (util-linux 2.23.).
 
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
 
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xbcd17d69.
 
Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   e   extended
Select (default p): p
Partition number (-, default ):
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ):
Using default value
Partition  of type Linux and of size  GiB is set
 
Command (m for help): p
 
Disk /dev/sdb: 10.7 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk label type: dos
Disk identifier: 0xbcd17d69
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1                         Linux
 
Command (m for help): w
The partition table has been altered!
 
Calling ioctl() to re-read partition table.
Syncing disks.
[root@mail ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42. (-Dec-)
Filesystem label=
OS type: Linux
Block size= (log=)
Fragment size= (log=)
Stride= blocks, Stripe width= blocks
 inodes,  blocks
 blocks (5.00%) reserved for the super user
First data block=
Maximum filesystem blocks=
 block groups
 blocks per group,  fragments per group
 inodes per group
Superblock backups stored on blocks:
    , , , , , , , 
 
Allocating group tables: done
Writing inode tables: done
Creating journal ( blocks): done
Writing superblocks and filesystem accounting information: done 
 
[root@mail ~]# mkdir /mnt/home          #创建一个目录
[root@mail ~]# mount /dev/sdb1 /mnt/home   #测试挂载下

4.4.创建用户

[root@mail ~]# vim adduserbat.sh  #创建一个添加用户的脚本
[root@mail ~]# cat adduserbat.sh  #确认下脚本
#!/bin/bash
 
groupadd usergrp
for user in user1 user2 user3 user4 user5
do
    useradd -g usergrp -b /mnt/home $user
    echo $user |passwd --stdin $user
done
[root@mail ~]# sh adduserbat.sh    #运行脚本去创建用户
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
Creating mailbox file: File exists
Changing password for user user1.
passwd: all authentication tokens updated successfully.
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
Creating mailbox file: File exists
Changing password for user user2.
passwd: all authentication tokens updated successfully.
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
Creating mailbox file: File exists
Changing password for user user3.
passwd: all authentication tokens updated successfully.
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
Creating mailbox file: File exists
Changing password for user user4.
passwd: all authentication tokens updated successfully.
useradd: warning: the home directory already exists.
Not copying any file from skel directory into it.
Creating mailbox file: File exists
Changing password for user user5.
passwd: all authentication tokens updated successfully.
[root@mail ~]# finger user1             #查看用户信息，确保家目录在/dev/sdb1的挂载目录上。
Login: user1                      Name:
Directory: /mnt/home/user1              Shell: /bin/bash
Never logged in.
No mail.
No Plan.
[root@mail ~]# id user1              #查看用户信息
uid=(user1) gid=(usergrp) groups=(usergrp)

4.5.检查操作系统支持

前面提到了quota仅仅针对整个文件系统来进行规划的。需要确认我们为各个用户提供存储的位置是独立的文件系统。

[root@mail ~]# df -h /mnt/home      #查看我们的挂载点是否是独立文件系统
Filesystem      Size  Used Avail Use% Mounted on
/dev/sdb1       .8G   37M  .2G   % /mnt/home
[root@mail ~]# mount |grep /mnt/home     #查看我们的文件系统
/dev/sdb1 on /mnt/home type ext4 (rw,relatime,data=ordered)

4.6.让文件系统支持quota设置

[root@mail ~]# mount -o remount,usrquota,grpquota /mnt/home   #重新挂载/mnt/home 支持usrquota,grpquota
[root@mail ~]# mount |grep /mnt/home                           #确认下
/dev/sdb1 on /mnt/home type ext4 (rw,relatime,quota,usrquota,grpquota,data=ordered)
[root@mail ~]# tail -n  /etc/mtab >> /etc/fstab         #追加到/etc/fstab中去，确保开机启用quota
[root@mail ~]# cat /etc/fstab                            #确保fstab文件正确性
 
#
# /etc/fstab
# Created by anaconda on Fri Feb  ::
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(), findfs(), mount() and/or blkid() for more info
#
/dev/mapper/cl-root     /                       xfs     defaults
UUID=dd4c6743-bdf5--a43b-814cbe75c618 /boot                   xfs     defaults
/dev/mapper/cl-swap     swap                    swap    defaults
/dev/sr0 /mnt/cdrom iso9660 ro,relatime,uid=,gid=,iocharset=utf8,mode=,dmode=
/dev/sdb1 /mnt/home ext4 rw,relatime,quota,usrquota,grpquota,data=ordered  

4.7.扫描文件系统并新建quota的配置文件

[root@mail ~]# quotacheck -avug
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/sdb1 [/mnt/home] done
quotacheck: Cannot stat old user quota file /mnt/home/aquota.user: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old group quota file /mnt/home/aquota.group: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old user quota file /mnt/home/aquota.user: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old group quota file /mnt/home/aquota.group: No such file or directory. Usage will not be subtracted.
quotacheck: Checked  directories and  files
quotacheck: Old file not found.
quotacheck: Old file not found.

主要参数

• -a:　　扫描所有在/etc/mtab内含有quota参数的文件系统
• -u:　　针对用户扫描文件与目录的使用情况，会新建一个aquota.user文件
• -g:　　针对用户组扫描文件与目录的使用情况，会新增一个aquota.group文件
• -v:　　显示扫描过程的信息

4.8 启用quota

[root@mail ~]# quotaon  -avug    #启用quota
/dev/sdb1 [/mnt/home]: group quotas turned on
/dev/sdb1 [/mnt/home]: user quotas turned on

这个命令（quotaon） 几乎只需要在第一次启动quota时才需要进行，因为下次等你重新启动时，系统的/etc/rc.d/rc.sysinit这个初始化脚本就会自动执行这个命令。

如果想关闭可以使用quotaoff -avug

4.9.编辑账户的的限值

[root@mail ~]# edquota -u user1

会打开一个vi编辑器，修改我们的设置如下图。

• 软限制： 这个值超过了基本上没事，还是可以创建文件继续使用文件，但是在指定grace天过后就不能在创建文件了。
• 硬限值： 这个值不能超过。

执行如下命令将user1的设置应用到其他用户上

[root@mail ~]# edquota -p user1 -u user2    #-p 指定参考用户，这句话的意思就是将user1的quota信息赋值给user2
[root@mail ~]# edquota -p user1 -u user3
[root@mail ~]# edquota -p user1 -u user4
[root@mail ~]# edquota -p user1 -u user5

4.10.编辑组的设置

[root@mail ~]# edquota -g usergrp

4.11.修改宽限时间

[root@mail ~]# edquota -t

4.12.对用户和组合quota限制查看

[root@mail ~]# quota -uvs user1       #查看user1的限制信息
Disk quotas for user user1 (uid ):
     Filesystem   space   quota   limit   grace   files   quota   limit   grace
      /dev/sdb1     28K    245M    293M
[root@mail ~]# quota -gvs usergrp
Disk quotas for group usergrp (gid ): #查看usergrp的限制信息
     Filesystem   space   quota   limit   grace   files   quota   limit   grace
      /dev/sdb1      0K    879M    977M                                     

参数说明

• -u:　　指定用户
• -g:　　指定用户组
• -s:　　以1024为倍数来指定单位，显示M之类的单位
• -v:　　显示用户在文件系统的quota值

4.13对文件系统quota限制查看

[root@mail ~]# repquota -as
*** Report for user quotas on device /dev/sdb1                   #这里看到是针对/dev/sdb1的文件系统的
Block grace time: 14days; Inode grace time: 7days
                        Space limits                File limits
User            used    soft    hard  grace    used  soft  hard  grace
----------------------------------------------------------------------
root      --     20K      0K      0K
zhao      --     52K      0K      0K
user1     --     28K    245M    293M
user2     --     28K    245M    293M
user3     --     28K    245M    293M
user4     --     28K    245M    293M
user5     --     28K    245M    293M                               

4.14.quota测试

[user1@mail ~]$ dd if=/dev/zero of=bigfile bs=1M count=270  #先创建一个270M的文件看看
sdb1: warning, user block quota exceeded.                   #这里提示警告了。 也就是我们超过了软限制的值250了。
+ records in
+ records out
 bytes ( MB) copied, 0.715086 s,  MB/s
[user1@mail ~]$ dd if=/dev/zero of=bigfile2 bs=1M count=40  #这里我们创建一个40M的文件
sdb1: write failed, user block limit reached.               #提示错误了。超出限制了。
dd: error writing ‘bigfile2’: Disk quota exceeded
+ records in
+ records out
 bytes ( MB) copied, 0.1165 s,  MB/s
[user1@mail ~]$ du -sk                                      #查看两个文件占用情况
    .

4.12脚本设置quota信息

上面我们对用户和组的设置，它会启动一个vi编辑器，修改保存才生效。需要交互。如果我们想使用script方式快速设置，那就需要使用setquota命令了。

命令使用  setquota  [  -u  | -g ] 用户名或者组名 块大小软限制 块大小硬限制  文件数量软限制 文件数量大小硬限制 文件系统

[root@mail ~]# quota -usv user1     #查看user1的quota信息
Disk quotas for user user1 (uid ):
     Filesystem   space   quota   limit   grace   files   quota   limit   grace
      /dev/sdb1    293M*   245M    293M  13days
[root@mail ~]# setquota -u user1     /dev/sdb1    #使用setquota修改
[root@mail ~]# quota -usv user1                                     #再次查看quota信息
Disk quotas for user user1 (uid ):
     Filesystem   space   quota   limit   grace   files   quota   limit   grace
      /dev/sdb1    293M    391M    489M