如果您的 Linux 服务器有多个用户经常存取数据时,为了维护所有使用者在硬盘容量的公平使用,磁碟配额 (Quota) 就是一项非常有用的工具,另外,如果你的用户常常抱怨磁盘容量不够用,那么更进阶的文件系统就得要学习,本章我们会介绍磁盘阵列 (RAID),及逻辑卷轴文件系统 (LVM),这些工具都可以帮助你管理与维护使用者可用的磁盘容量.
Quota 磁盘配额配置
Quota 这个玩意儿就字面上的意思来看,就是有多少『限额』的意思啦,如果是用在零用钱上面,就是类似『有多少零用钱一个月』的意思之类的,如果是在计算机主机的磁盘使用量上呢? 以 Linux 来说,就是有多少容量限制的意思,我们可以使用 quota 来让磁盘的容量使用较为公平,下面我们会介绍什么是 quota 然后以一个完整的范例来介绍 quota 的使用作用.
由于Linux是一个多用户管理的操作系统，而Linux默认情况下并不限制每个用户使用磁盘空间的大小，假如某个用户疏忽或者恶意占满磁盘空间，将导致系统磁盘无法写入甚至崩溃；为了保证系统磁
盘的有足够的剩余空间，我们需要对用户和组进行磁盘空间使用限制。
磁盘配额限制类型：
⦁ 限制用户和组,对磁盘空间的使用量
⦁ 限制用户和组,在磁盘内创建文件的个数
磁盘配额限制级别：
⦁ 软限制：低级限制,此限制可以突破,突破时会被警告,超出部分会有宽限天数,宽限天数到期后超出部分被清空,软限制不能超过硬限制
⦁ 硬限制：绝对限制,此限制不会被突破,达到指定限制后无法使用更多空间
⦁ 宽限天数：当有数据超过软限制后,超出部分会被计时,宽限天数到期后超出部分数据将被清空,宽限天数默认是7天
注：磁盘配额是针对分区进行设置的,无法实现,"某用户在系统中共计只能使用50MB磁盘空间",只能设置某用户在/home分区能使用30M这样的限制.切记：磁盘配额是针对分区的!
精简模式下没有此命令,执行 yum install -y quota 安装
◆检查内核是否支持配额◆
[root@localhost ~]# cat /boot/config-3.10.0-693.el7.x86_64 |grep "CONFIG_QUOTA"
CONFIG_QUOTA=y
CONFIG_QUOTA_NETLINK_INTERFACE=y
# CONFIG_QUOTA_DEBUG is not set
CONFIG_QUOTA_TREE=y
CONFIG_QUOTACTL=y
CONFIG_QUOTACTL_COMPAT=y◆检查指定分区的挂载属性是否满足条件◆
[root@localhost ~]# dumpe2fs -h /dev/vdb |grep "Default mount options"
dumpe2fs 1.42.9 (28-Dec-2013)
Default mount options: user_xattr acl
#检查结果中是否包含,usrquota,grpquota两个挂载属性◆quotacheck 生成用户和组的配置文件◆
[root@localhost ~]# quotacheck --help
Utility for checking and repairing quota files.
quotacheck [-gucbfinvdmMR] [-F ] filesystem|-a
语法格式：[ quota [选项] [分区名] ]
-a #扫描/etc/mtab文件中所有启用磁盘配额功能的分区.如果加入此参数,命令后面就不需要加入分区名了
-u #建立用户配额的配置文件,即生成aquota.user
-g #建立组配额的配置文件,即aquota.group
-v #显示扫描过程
-c #清除原有的配置文件,重新建立新的配置文件 ◆edquota 编辑配额文件,设置指定限制大小◆
[root@localhost ~]# edquota --help
edquota: Usage:
edquota [-rm] [-u] [-F formatname] [-p username] [-f filesystem] username ...
edquota [-rm] -g [-F formatname] [-p groupname] [-f filesystem] groupname ...
edquota [-u|g] [-F formatname] [-f filesystem] -t
edquota [-u|g] [-F formatname] [-f filesystem] -T username|groupname ...
语法格式：[ edquota [选项] [用户名或组名] ]
-u #用户名
-g #组名
-t #设定宽限时间
-p #复制磁盘配额规则,不需要每一个用户或者组都手动设置一遍
#edquota -p 模板用户 -u 目标用户
#注：配置文件中所写大小默认单位KB◆启动quota配额管理◆
[root@localhost ~]# quotaon --help
quotaon: Usage:
quotaon [-guvp] [-F quotaformat] [-x state] -a
quotaon [-guvp] [-F quotaformat] [-x state] filesys ...
语法格式：[ quotaon [选项] [分区名] ]
-a #根据/etc/mtab文件启动所有分区的磁盘配额（不写分区名）
-u #启动用户的磁盘配额
-g #启动组的磁盘配额
-v #显示启动过程信息◆关闭quota配额管理◆
[root@localhost ~]# quotaoff --help
quotaoff: Usage:
quotaoff [-guvp] [-F quotaformat] [-x state] -a
quotaoff [-guvp] [-F quotaformat] [-x state] filesys ...
语法格式：[ quotaoff [选项] [分区名] ]
-a #根据/etc/mtab文件关闭所有分区的磁盘配额（不写分区名）
-u #关闭用户的磁盘配额
-g #关闭组的磁盘配额
-v #显示关闭过程信息◆quota 查看指定用户和组的配额信息◆
[root@localhost ~]# quota --hlep
quota: unrecognized option '--hlep'
quota: Usage: quota [-guqvswim] [-l | [-Q | -A]] [-F quotaformat]
quota [-qvswim] [-l | [-Q | -A]] [-F quotaformat] -u username ...
quota [-qvswim] [-l | [-Q | -A]] [-F quotaformat] -g groupname ...
quota [-qvswugQm] [-F quotaformat] -f filesystem ...
语法格式：[ quota [选项] [用户名] ]
-u #用户名
-g #组名
-v #显示详细信息
-s #以常见单位显示大小◆repquota 查看指定分区的磁盘配额◆
[root@localhost ~]# repquota --help
repquota: Utility for reporting quotas.
Usage:
repquota [-vugsi] [-c|C] [-t|n] [-F quotaformat] (-a | mntpoint)
语法格式：[ repquota [选项] [分区名] ]
-u #查询用户配额
-g #查询组配额
-v #显示详情
-s #以常见单位显示◆setquota 非交互设置磁盘配额命令◆
[root@localhost ~]# setquota --help
setquota: Usage:
setquota [-u|-g] [-rm] [-F quotaformat]
-a|...
setquota [-u|-g] [-rm] [-F quotaformat] <-p protouser|protogroup> -a|...
setquota [-u|-g] [-rm] [-F quotaformat] -b [-c] -a|...
setquota [-u|-g] [-F quotaformat] -t -a|...
setquota [-u|-g] [-F quotaformat] -T -a|...
setquota -u 用户名 软(容) 硬(容) 软(数) 硬(数) 分区名
注：这样的非交互式的命令更适合写入脚本,而且假如有很多用户的磁盘配额配置相同也可以用复制来实现。 ◆磁盘配额小实验◆
⦁ 这里有一块未分区的磁盘/dev/sdb,手动分区并格式化.
⦁ 将磁盘配额开启,并写入开机自启动列表.
⦁ 创建lyshark用户,和temp组.
⦁ 配置lyshark的软限制200M,硬限制500M,配置temp组软限制100M,硬限制200M.
1.检查系统是否支持配额
[root@localhost ~]# cat /boot/config-3.10.0-862.el7.x86_64 |grep "CONFIG_QUOTA"
CONFIG_QUOTA=y
CONFIG_QUOTA_NETLINK_INTERFACE=y
# CONFIG_QUOTA_DEBUG is not set
CONFIG_QUOTA_TREE=y
CONFIG_QUOTACTL=y
CONFIG_QUOTACTL_COMPAT=y2.查看磁盘信息
[root@localhost ~]# ll /dev/sd*
brw-rw---- 1 root disk 8, 0 6月 24 09:14 /dev/sda
brw-rw---- 1 root disk 8, 1 6月 24 09:14 /dev/sda1
brw-rw---- 1 root disk 8, 2 6月 24 09:14 /dev/sda2
brw-rw---- 1 root disk 8, 16 6月 24 09:14 /dev/sdb3.磁盘分区/dev/sdb,并格式化为ext4格式
[root@localhost ~]# parted /dev/sdb
GNU Parted 3.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mkpart
Partition name? []? sdb1
File system type? [ext2]? ext2
Start? 1M
End? 10000M
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 10.0GB 9999MB ext4 sdb1
(parted) q
Information: You may need to update /etc/fstab.
[root@localhost ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
610800 inodes, 2441216 blocks
122060 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2151677952
75 block groups
32768 blocks per group, 32768 fragments per group
8144 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done4.创建挂载点,并挂载设备
[root@localhost ~]# mkdir /sdb1
[root@localhost ~]# mount /dev/sdb1 /sdb1/
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.4G 6.7G 17% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 6% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/sr0 4.2G 4.2G 0 100% /mnt
/dev/sdb1 9.1G 37M 8.6G 1% /sdb15.检查分区是否支持配额 (主要看有没有usrquota,grpquota)
[root@localhost ~]# dumpe2fs -h /dev/sdb1 |grep "Default mount options"
dumpe2fs 1.42.9 (28-Dec-2013)
Default mount options: user_xattr acl
[root@localhost ~]# cat /proc/mounts |grep "/dev/sdb1"
/dev/sdb1 /sdb1 ext4 rw,relatime,data=ordered 0 0
#上面没有看到相关权限,此时我们要重新挂载一下磁盘,加上权限
[root@localhost ~]# mount -o remount,usrquota,grpquota /dev/sdb1
[root@localhost ~]# cat /proc/mounts |grep "/dev/sdb1"
/dev/sdb1 /sdb1 ext4 rw,relatime,quota,usrquota,grpquota,data=ordered 0 06.设置开机自动挂载分区,并开启配额
[root@localhost ~]# ls -l /dev/disk/by-uuid/
total 0
lrwxrwxrwx 1 root root 10 Sep 21 20:07 13d5ccc2-52db-4aec-963a-f88e8edcf01c -> ../../sda1
lrwxrwxrwx 1 root root 9 Sep 21 20:07 2018-05-03-20-55-23-00 -> ../../sr0
lrwxrwxrwx 1 root root 10 Sep 21 20:07 4604dcf2-da39-455a-9719-e7c5833e566c -> ../../dm-0
lrwxrwxrwx 1 root root 10 Sep 21 20:47 939cbeb8-bc88-44aa-9221-50672111e123 -> ../../sdb1
lrwxrwxrwx 1 root root 10 Sep 21 20:07 f6a4b420-aa6a-4e66-bbb3-c8e8280a099f -> ../../dm-1
[root@localhost ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Tue Sep 18 09:05:06 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
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=13d5ccc2-52db-4aec-963a-f88e8edcf01c /boot xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
UUID=7d7f22ed-466e-4205-8efe-1b6184dc5e1b swap swap defaults 0 0
UUID=939cbeb8-bc88-44aa-9221-50672111e123 /sdb1 ext4 defaults,usrquota,grpquota 0 0
[root@localhost ~]# mount -o remount,usrquota,grpquota /dev/sdb17.生成配额文件 quotackeck -ugv[分区名]
[root@localhost ~]# quotacheck -ugv /dev/sdb1
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 [/sdb1] done
quotacheck: Cannot stat old user quota file /sdb1/aquota.user: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old group quota file /sdb1/aquota.group: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old user quota file /sdb1/aquota.user: No such file or directory. Usage will not be subtracted.
quotacheck: Cannot stat old group quota file /sdb1/aquota.group: No such file or directory. Usage will not be subtracted.
quotacheck: Checked 3 directories and 0 files
quotacheck: Old file not found.
quotacheck: Old file not found.8.编辑限制,edquota -ugtp [用户名/组名]
配置lyshark的软限制200M,硬限制500M
[root@localhost ~]# edquota -u lyshark
Disk quotas for user lyshark (uid 1000):
↓文件系统 软(容量) 硬(容量) I节点 软(数) 硬(数)
Filesystem blocks soft hard inodes soft hard
/dev/sdb1 0 200M 500M 0 0 0配置temp组软限制100M,硬限制200M.
[root@localhost ~]# edquota -g temp
Disk quotas for group temp (gid 1001):
Filesystem blocks soft hard inodes soft hard
/dev/sdb1 0 102400 204800 0 0 09.开启配额,quota on/off -augv
[root@localhost ~]# quotaon -augv
/dev/sdb1 [/sdb1]: group quotas turned on
/dev/sdb1 [/sdb1]: user quotas turned on10.查看指定用户或组的配额,quota -ugvs
[root@localhost ~]# quota -ugvs
Disk quotas for user root (uid 0):
Filesystem space quota limit grace files quota limit grace
/dev/sdb1 20K 0K 0K 2 0 0
Disk quotas for group root (gid 0):
Filesystem space quota limit grace files quota limit grace
/dev/sdb1 20K 0K 0K 2 0 0LVM 逻辑卷管理器
LVM（Logical Volume Manager）逻辑卷管理,它是Linux环境下对磁盘分区进行管理的一种机制,普通的磁盘分区管理方式在分区划分好之后就无法改变其大小,当一个逻辑分区存放不下某个文件时,解决的方法通常是使用符号链接,或者使用调整分区大小的工具,但这只是暂时解决办法,没有从根本上解决问题.简单来说LVM就是将物理磁盘融合成一个或几个大的虚拟磁盘存储池,按照我们的需求去存储池划分空间来使用,由于是虚拟的存储池,所以划分空间时可以自由的调整大小,如下：
LVM的组成部分：
⦁ 物理卷（PV，Physical Volume）：由磁盘或分区转化而成
⦁ 卷组（VG，Volume Group）：将多个物理卷组合在一起组成了卷组,组成同一个卷组的可以是同一个硬盘的不同分区,也可以是不同硬盘上的不同分区,我们通常把卷组理解为一块硬盘.
⦁ 逻辑卷（LV，Logical Volume）：把卷组理解为硬盘的话,那么我们的逻辑卷则是硬盘上的分区,逻辑卷可以进行格式化,存储数据.
⦁ 物理扩展（PE，Physical Extend）：PE卷组的最小存储单元,PE所在的位置是VG卷组,即硬盘上,那么我们可以把PE理解为硬盘上的扇区,默认是4MB,可自由配置.
这里准备好4块硬盘,无需分区与格式化.
[root@localhost ~]# ll /dev/sd[b-z]
brw-rw---- 1 root disk 8, 16 Sep 21 22:04 /dev/sdb
brw-rw---- 1 root disk 8, 32 Sep 21 22:04 /dev/sdc
brw-rw---- 1 root disk 8, 48 Sep 21 22:04 /dev/sdd
brw-rw---- 1 root disk 8, 64 Sep 21 22:04 /dev/sde◆PV 物理卷创建与移除◆
PV的创建
pvcreate [分区路径],[分区路径][.......]
[root@localhost ~]# ll /dev/sd[b-z]
brw-rw---- 1 root disk 8, 16 Sep 21 22:04 /dev/sdb
brw-rw---- 1 root disk 8, 32 Sep 21 22:04 /dev/sdc
brw-rw---- 1 root disk 8, 48 Sep 21 22:04 /dev/sdd
brw-rw---- 1 root disk 8, 64 Sep 21 22:04 /dev/sde
[root@localhost ~]# pvcreate /dev/sdb /dev/sdc #此处拿3块硬盘创建
Physical volume "/dev/sdb" successfully created.
Physical volume "/dev/sdc" successfully created.
Physical volume "/dev/sdd" successfully created.
[root@localhost ~]# pvs #查询创建好的硬盘
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb lvm2 --- 10.00g 10.00g
/dev/sdc lvm2 --- 10.00g 10.00g
/dev/sdd lvm2 --- 10.00g 10.00gPV的移除
pvremove [分区路径]
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb lvm2 --- 10.00g 10.00g
/dev/sdc lvm2 --- 10.00g 10.00g
/dev/sdd lvm2 --- 10.00g 10.00g
[root@localhost ~]# pvremove /dev/sdd #移除/dev/sdd
Labels on physical volume "/dev/sdd" successfully wiped.
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb lvm2 --- 10.00g 10.00g
/dev/sdc lvm2 --- 10.00g 10.00g◆VG 卷组创建与移除◆
创建VG卷组,VG卷组要在PV中选择
vgcreate -s [指定PE大小] [VG卷组名] [分区路径] [分区路径][.....]
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb lvm2 --- 10.00g 10.00g
/dev/sdc lvm2 --- 10.00g 10.00g
[root@localhost ~]# vgcreate -s 4M my_vg /dev/sdb /dev/sdc #此处就是创建一个VG卷组
Volume group "my_vg" successfully created
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <9.00g 0
my_vg 2 0 0 wz--n- 19.99g 19.99g #这就是VG卷组,名字是my_vg给当前my_vg卷组,添加一块新的PV,也就是扩展卷组
vgextend [卷组名] [物理卷分区]
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb my_vg lvm2 a-- <10.00g <10.00g
/dev/sdc my_vg lvm2 a-- <10.00g <10.00g
/dev/sdd lvm2 --- 10.00g 10.00g #这个物理卷没有划分卷组
[root@localhost ~]# vgextend my_vg /dev/sdd #添加一个PV到指定卷组
Volume group "my_vg" successfully extended
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb my_vg lvm2 a-- <10.00g <10.00g
/dev/sdc my_vg lvm2 a-- <10.00g <10.00g
/dev/sdd my_vg lvm2 a-- <10.00g <10.00g #已被划分到my_vg卷组在VG卷组里移除一个PV（移除单个PG）
vgreduce [卷组名] [物理卷分区]
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb my_vg lvm2 a-- <10.00g <10.00g
/dev/sdc my_vg lvm2 a-- <10.00g <10.00g
/dev/sdd my_vg lvm2 a-- <10.00g <10.00g
[root@localhost ~]# vgreduce my_vg /dev/sdd #将/dev/sdd从my_vg卷组里移除
Removed "/dev/sdd" from volume group "my_vg"
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <9.00g 0
/dev/sdb my_vg lvm2 a-- <10.00g <10.00g
/dev/sdc my_vg lvm2 a-- <10.00g <10.00g
/dev/sdd lvm2 --- 10.00g 10.00g移除整个VG卷组
vgremove [卷组名]
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <9.00g 0
my_vg 2 0 0 wz--n- 19.99g 19.99g
[root@localhost ~]# vgremove my_vg #移除整个卷组
Volume group "my_vg" successfully removed
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <9.00g 0
[root@localhost ~]#
移除空的物理卷VG
vgreduce -a [卷组名]
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <9.00g 0
my_vg 3 0 0 wz--n- <29.99g <29.99g
[root@localhost ~]# vgreduce -a my_vg #只移除空卷组
Removed "/dev/sdb" from volume group "my_vg"
Removed "/dev/sdc" from volume group "my_vg"
[root@localhost ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <9.00g 0
my_vg 1 0 0 wz--n- <10.00g <10.00g
◆LV 逻辑卷创建与移除◆
创建LVM
lvcreate -L [指定大小] -n [LV名字] [VG卷组:从哪个卷组里划分]
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- <8.00g
swap centos -wi-ao---- 1.00g
[root@localhost ~]# lvcreate -L 10G -n my_lv my_vg #创建LVM逻辑卷
Logical volume "my_lv" created.
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- <8.00g
swap centos -wi-ao---- 1.00g
my_lv my_vg -wi-a----- 10.00g格式化并挂载使用
[root@localhost ~]# mkdir /LVM #首先创建一个挂载点
[root@localhost ~]#
[root@localhost ~]# mkfs.ext4 /dev/my_vg/my_lv #格式化LVM分区
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
655360 inodes, 2621440 blocks
131072 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2151677952
80 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@localhost ~]# mount /dev/my_vg/my_lv /LVM/ #挂载LVM
[root@localhost ~]#
[root@localhost ~]# df -h #查看结果
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 5% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/mapper/my_vg-my_lv 9.8G 37M 9.2G 1% /LVM ← 挂载成功
◆LV 容量增加 (将LV的容量增加5G的空间)◆
注意：这里扩展,要先扩展LVM,然后再扩展文件系统
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 5% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/mapper/my_vg-my_lv 9.8G 37M 9.2G 1% /LVM ←此处是10G
[root@localhost ~]# lvextend -L +5G /dev/my_vg/my_lv #执行增加命令,从VG卷组划分5G
Size of logical volume my_vg/my_lv changed from 10.00 GiB (2560 extents) to 15.00 GiB (3840).
Logical volume my_vg/my_lv successfully resized.
[root@localhost ~]# resize2fs -f /dev/my_vg/my_lv #扩展文件系统
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/my_vg/my_lv is mounted on /LVM; on-line resizing required
old_desc_blocks = 2, new_desc_blocks = 2
The filesystem on /dev/my_vg/my_lv is now 3932160 blocks long.
[root@localhost ~]# df -h #验证扩展结果
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 5% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/mapper/my_vg-my_lv 15G 41M 14G 1% /LVM ←此处已经从10G 增加到15G◆LV 容量缩小(将LV的容量缩小5G的空间)◆
注意：这里缩小,要卸载文件系统,检查分区,然后缩小文件系统,最后再缩小LVM
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 5% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/mapper/my_vg-my_lv 15G 41M 14G 1% /LVM ←此处显示15G空间
[root@localhost ~]# umount /dev/my_vg/my_lv #卸载LVM卷组
[root@localhost ~]# e2fsck -f /dev/my_vg/my_lv #检查文件系统
e2fsck 1.42.9 (28-Dec-2013)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/my_vg/my_lv: 11/983040 files (0.0% non-contiguous), 104724/3932160 blocks
[root@localhost ~]# resize2fs -f /dev/my_vg/my_lv 10G(减小后的大小) #缩小文件系统
resize2fs 1.42.9 (28-Dec-2013)
Resizing the filesystem on /dev/my_vg/my_lv to 2621440 (4k) blocks.
The filesystem on /dev/my_vg/my_lv is now 2621440 blocks long.
[root@localhost ~]# lvreduce -L 10G /dev/my_vg/my_lv #缩小LVM
WARNING: Reducing active logical volume to 10.00 GiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce my_vg/my_lv? [y/n]: y #输入y
Size of logical volume my_vg/my_lv changed from 15.00 GiB (3840 extents) to 10.00 GiB (2560).
Logical volume my_vg/my_lv successfully resized.
[root@localhost ~]# mount /dev/my_vg/my_lv /LVM/ #挂载
[root@localhost ~]# df -h #再次查看分区变化
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
tmpfs 110M 0 110M 0% /dev/shm
tmpfs 110M 5.5M 104M 5% /run
tmpfs 110M 0 110M 0% /sys/fs/cgroup
/dev/sda1 1014M 130M 885M 13% /boot
tmpfs 22M 0 22M 0% /run/user/0
/dev/mapper/my_vg-my_lv 9.8G 37M 9.2G 1% /LVM ←此处已经从15G变成10G◆LV 快照功能◆
拍摄快照
lvcreate [-s 快照] -n [快照名] -L [快照大小] [指定分区]
[root@localhost LVM]# ls
1 12 16 2 23 27 30 34 38 41 45 49 52 56 6 63 67 70 74 78 81 85 89 92 96
10 13 17 20 24 28 31 35 39 42 46 5 53 57 60 64 68 71 75 79 82 86 9 93 97
100 14 18 21 25 29 32 36 4 43 47 50 54 58 61 65 69 72 76 8 83 87 90 94 98
11 15 19 22 26 3 33 37 40 44 48 51 55 59 62 66 7 73 77 80 84 88 91 95 99
[root@localhost LVM]# lvcreate -s -n mylv_back -L 200M /dev/my_vg/my_lv #给/LVM目录拍摄快照
Logical volume "mylv_back" created.
[root@localhost LVM]# lvs #查看快照
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- <8.00g
swap centos -wi-ao---- 1.00g
my_lv my_vg owi-aos--- 10.00g
mylv_back my_vg swi-a-s--- 200.00m my_lv 0.01 ←此处就是快照快照恢复
[root@localhost LVM]# ls
1 12 16 2 23 27 30 34 38 41 45 49 52 56 6 63 67 70 74 78 81 85 89 92 96
10 13 17 20 24 28 31 35 39 42 46 5 53 57 60 64 68 71 75 79 82 86 9 93 97
100 14 18 21 25 29 32 36 4 43 47 50 54 58 61 65 69 72 76 8 83 87 90 94 98
11 15 19 22 26 3 33 37 40 44 48 51 55 59 62 66 7 73 77 80 84 88 91 95 99
[root@localhost LVM]# rm -fr * #模拟被删除
[root@localhost LVM]# mkdir /back #创建挂载点
[root@localhost LVM]# mount /dev/my_vg/mylv_back /back/ #挂载备份文件
[root@localhost LVM]# cp -a /back/* ./ #复制备份文件
[root@localhost LVM]# ls
1 12 16 2 23 27 30 34 38 41 45 49 52 56 6 63 67 70 74 78 81 85 89 92 96
10 13 17 20 24 28 31 35 39 42 46 5 53 57 60 64 68 71 75 79 82 86 9 93 97
100 14 18 21 25 29 32 36 4 43 47 50 54 58 61 65 69 72 76 8 83 87 90 94 98
11 15 19 22 26 3 33 37 40 44 48 51 55 59 62 66 7 73 77 80 84 88 91 95 99RAID 独立磁盘冗余阵列
定义：独立磁盘构成的具有冗余能力的阵列
磁盘阵列分类：一是外接式磁盘阵列柜、二是内接式磁盘阵列卡，三是利用软件来仿真
1.通过把多个磁盘组织在一起作为一个逻辑卷提供磁盘跨越功能
2.通过把数据分成多个数据块（Block）并行写入/读出多个磁盘以提高访问磁盘的速度
3.通过镜像或校验操作提供容错能力
注意：RAID磁盘阵列主要为了保证硬件损坏的情况下业务不会终止，无法防止误操作
磁盘阵列的分类
1.外接式磁盘阵列柜
2.内接式磁盘阵列
3.利用软件来仿真
注意：通常情况下,生产环境中,一般使用硬件RAID来做,这里只做了解即可
RAID磁盘阵列简介
RAID 0 没有奇偶校验的 (条带卷)
RAID 0 提高存储性能的原理是把连续的数据分散到多个磁盘上存取,这样系统有数据请求就可以被多个磁盘并行的执行,每个磁盘执行属于它自己的那部分数据请求
RAID 1 独立磁盘冗余阵 (镜像卷)
RAID 1 通过磁盘数据镜像实现数据冗余,在成对的独立磁盘上产生互为备份的数据.当原始数据繁忙时,可直接从镜像拷贝中读取数据,因此RAID 1可以提高读取性能.
RAID10 (镜象阵列条带)
Raid 10 是一个Raid1与Raid0的组合体,它是利用奇偶校验实现条带集镜像,所以它继承了Raid0的快速和Raid1的安全.
RAID5 分布式奇偶校验的独立磁盘结构(最少3块)
RAID 5 是一种存储性能,数据安全,和存储成本,兼顾的存储解决方案. RAID 5可以理解为是RAID 0和RAID 1的折中方案.
◆Mdadm 命令解析◆
[root@localhost ~]# mdadm --help
mdadm is used for building, managing, and monitoring
Linux md devices (aka RAID arrays)
Usage: mdadm
mdadm --create --auto=yes /dev/md[0-9] --raid-devices=[0-n] \
--level=[015] --spare-devices=[0-n] /dev/sd[a-z]
--create #新建RAID参数
--auto=yes #默认配置
--raid-devices=N #磁盘阵列数
--spare-devices=N #备份磁盘数
--level [015] #阵列等级
mdadm --detail #查询阵列信息◆构建一个RAID 5◆
注意：精简模式下,没有安装此命令,执行 yum install -y mdadm 安装
[root@localhost ~]# ls -l /dev/sd[b-z]
brw-rw---- 1 root disk 8, 16 Sep 21 23:06 /dev/sdb
brw-rw---- 1 root disk 8, 32 Sep 21 23:06 /dev/sdc
brw-rw---- 1 root disk 8, 48 Sep 21 23:06 /dev/sdd
brw-rw---- 1 root disk 8, 64 Sep 21 23:04 /dev/sde
[root@localhost ~]# mdadm --create --auto=yes /dev/md0 --level=5 \
> --raid-devices=3 --spare-devices=1 /dev/sd{b,c,d,e} #创建一个RAID,其中接口是/dev/md0,等级是RAID5
mdadm: Defaulting to version 1.2 metadata #主磁盘数3,备份盘数1,提供sd{b,c,d,e}磁盘
mdadm: array /dev/md0 started.
[root@localhost ~]# mdadm --detail /dev/md0 #查看阵列信息
/dev/md0: ←设备文件名
Version : 1.2
Creation Time : Fri Sep 21 23:19:09 2018 ←创建日期
Raid Level : raid5 ←RAID等级
Array Size : 20953088 (19.98 GiB 21.46 GB) ←可用空间
Used Dev Size : 10476544 (9.99 GiB 10.73 GB) ←每个设备可用空间
Raid Devices : 3 ←RAID设备数量
Total Devices : 4 ←全部设备数量
Persistence : Superblock is persistent
Update Time : Fri Sep 21 23:19:26 2018
State : clean, degraded, recovering
Active Devices : 3 ←启动磁盘
Working Devices : 4 ←可用磁盘
Failed Devices : 0 ←错误磁盘
Spare Devices : 1 ←预备磁盘
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Rebuild Status : 34% complete
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : 2ee2bcd5:c5189354:d3810252:23c2d5a8 ←此设备UUID
Events : 6
Number Major Minor RaidDevice State
0 8 16 0 active sync /dev/sdb
1 8 32 1 active sync /dev/sdc
4 8 48 2 spare rebuilding /dev/sdd
3 8 64 - spare /dev/sde格式化 /dev/md0并挂载使用
[root@localhost ~]# mkfs -t ext4 /dev/md0 #格式化
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=128 blocks, Stripe width=256 blocks
1310720 inodes, 5238272 blocks
261913 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2153775104
160 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
[root@localhost ~]# mkdir /RAID #新建挂载目录
[root@localhost ~]#
[root@localhost ~]# mount /dev/md0 /RAID/ #挂载设备
[root@localhost ~]#
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 8.0G 1.2G 6.9G 15% /
devtmpfs 98M 0 98M 0% /dev
/dev/sr0 4.2G 4.2G 0 100% /mnt
/dev/md0 20G 45M 19G 1% /RAID ←此处可看到挂载成功◆RAID 仿真救援模式◆
mdadm --manage /dev/md[0-9] --add 设备 --remove 设备 --fail 设备
--add #将后面的设备加入md中
--remove #移除设备
--fail #设置出错磁盘
------------------------------------------------------------
[实验]
[root@localhost /]# mdadm --manage /dev/md0 --fail /dev/sdb #将/dev/sdb标注为错误
mdadm: set /dev/sdb faulty in /dev/md0
[root@localhost /]# mdadm --detail /dev/md0 #查看一下状态
/dev/md0:
Version : 1.2
Creation Time : Fri Sep 21 23:19:09 2018
Raid Level : raid5
Array Size : 20953088 (19.98 GiB 21.46 GB)
Used Dev Size : 10476544 (9.99 GiB 10.73 GB)
Raid Devices : 3
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Fri Sep 21 23:50:12 2018
State : clean, degraded, recovering
Active Devices : 2
Working Devices : 3
Failed Devices : 1 ← 出错磁盘一个
Spare Devices : 1
Layout : left-symmetric
Chunk Size : 512K
Consistency Policy : resync
Rebuild Status : 5% complete ←此处需要注意,他正在恢复数据,等到100%时又可以正常工作
Name : localhost.localdomain:0 (local to host localhost.localdomain)
UUID : 2ee2bcd5:c5189354:d3810252:23c2d5a8
Events : 20
Number Major Minor RaidDevice State
3 8 64 0 spare rebuilding /dev/sde
1 8 32 1 active sync /dev/sdc
4 8 48 2 active sync /dev/sdd
0 8 16 - faulty /dev/sdb ← 出错磁盘
[root@localhost /]# mdadm --manage /dev/md0 --remove /dev/sdb #移除这个坏掉的磁盘
mdadm: hot removed /dev/sdb from /dev/md0
[root@localhost /]# mdadm --manage /dev/md0 --add /dev/sdb #添加一个新的磁盘
mdadm: added /dev/sdb