LVM操作过程
(1)添加磁盘后测试：
[root@centos7-4 ~]# lsblk
(2)磁盘分区(只分一个区)：
[root@centos7-4 ~]# fdisk /dev/sdb
(3)创建物理卷(PV)
[root@lvm ~]# pvcreate /dev/sdb1
(4)创建逻辑卷组(VG)
[root@lvm ~]# vgcreate vg_cloud3 /dev/sdb1
(5)查看所有逻辑卷组
[root@lvm ~]# vgscan
(6)显示vg_cloud3卷组的详细信息
[root@lvm ~]# vgdisplay vg_cloud3
(7)创建逻辑卷(LV)
[root@lvm ~]# lvcreate -L +2G -n cloud3 vg_cloud3
(8)查看所有逻辑卷(LV)
[root@lvm ~]# lvscan
(9)格式化逻辑卷(LV)
[root@lvm ~]# mkfs.ext4 /dev/vg_cloud3/cloud3
(10)创建目录backup
[root@lvm ~]# mkdir backup
(11)开机挂载逻辑卷cloud3
[root@lvm ~]# vim /etc/fstab
/dev/vg_cloud3/cloud3 /root/backup ext4 defaults 0 0
(12)挂载所有
[root@lvm ~]# mount -a
(12)查看所有挂载点
[root@lvm ~]# df -hT
2.扩展逻辑卷/dev/vg_cloud3/cloud3空间
(1)扩展逻辑卷/dev/vg_cloud3/cloud3空间到4G
<1>查看卷组的剩余空间
[root@lvm ~]# vgdisplay vg_cloud3
--- Volume group ---
VG Name vg_cloud3
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size <5.00 GiB
PE Size 4.00 MiB
Total PE 1279
Alloc PE / Size 512 / 2.00 GiB
Free PE / Size 767 / <3.00 GiB
VG UUID gFIuXV-UlJH-g2dH-bYin-VWdl-a4Qj-tZEHoP
<2>扩展逻辑卷/dev/vg_cloud3/cloud3的物理空间
[root@lvm ~]# lvextend -L +2G /dev/vg_cloud3/cloud3
Size of logical volume vg_cloud3/cloud3 changed from 2.00 GiB (512 extents) to 4.00 GiB (1024 extents).
Logical volume vg_cloud3/cloud3 successfully resized.
<3>再次查看挂载点显示该逻辑卷并没有被物理扩容
[root@lvm ~]# df -hT
文件系统 类型 容量 已用 可用 已用% 挂载点
/dev/mapper/centos-root xfs 17G 10G 7.1G 59% /
devtmpfs devtmpfs 473M 0 473M 0% /dev
tmpfs tmpfs 489M 0 489M 0% /dev/shm
tmpfs tmpfs 489M 14M 475M 3% /run
tmpfs tmpfs 489M 0 489M 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 161M 854M 16% /boot
tmpfs tmpfs 98M 8.0K 98M 1% /run/user/42
tmpfs tmpfs 98M 24K 98M 1% /run/user/1000
tmpfs tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/vg_cloud3-cloud3 ext4 2.0G 6.0M 1.8G 1% /root/backup
<4>调整逻辑卷分区的大小(扩展文件系统)
[root@lvm ~]# resize2fs /dev/vg_cloud3/cloud3
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/vg_cloud3/cloud3 is mounted on /root/backup; on-line resizing re quired
old_desc_blocks = 1, new_desc_blocks = 1
The filesystem on /dev/vg_cloud3/cloud3 is now 1048576 blocks long.
[root@lvm ~]# lvscan
ACTIVE '/dev/centos/swap' [2.00 GiB] inherit
ACTIVE '/dev/centos/root' [<17.00 GiB] inherit
ACTIVE '/dev/vg_cloud3/cloud3' [4.00 GiB] inherit
备注：resize2fs只适用于ext3/ext4文件系统；xfs文件系统用xfs_growfs
(2)由于卷组空间不足需添加新磁盘让逻辑卷扩大到10G容量.
<1>查看块设备
[root@lvm ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 19G 0 part
├─centos-root 253:0 0 17G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 5G 0 disk
└─sdb1 8:17 0 5G 0 part
└─vg_cloud3-cloud3 253:2 0 4G 0 lvm /root/backup
sdc 8:32 0 10G 0 disk
sr0 11:0 1 1024M 0 rom
<2>创建物理卷(PV)
[root@lvm ~]# pvcreate /dev/sdc
Physical volume "/dev/sdc" successfully created.
[root@lvm ~]# pvscan
PV /dev/sda2 VG centos lvm2 [<19.00 GiB / 0 free]
PV /dev/sdb1 VG vg_cloud3 lvm2 [<5.00 GiB / 1020.00 MiB free]
PV /dev/sdc lvm2 [10.00 GiB]
Total: 3 [33.99 GiB] / in use: 2 [23.99 GiB] / in no VG: 1 [10.00 GiB]
[root@lvm ~]# vgextend vg_cloud3 /dev/sdc
Volume group "vg_cloud3" successfully extended
[root@lvm ~]# pvscan
PV /dev/sda2 VG centos lvm2 [<19.00 GiB / 0 free]
PV /dev/sdb1 VG vg_cloud3 lvm2 [<5.00 GiB / 1020.00 MiB free]
PV /dev/sdc VG vg_cloud3 lvm2 [<10.00 GiB / <10.00 GiB free]
Total: 3 [<33.99 GiB] / in use: 3 [<33.99 GiB] / in no VG: 0 [0 ]
[root@lvm ~]# vgdisplay vg_cloud3
--- Volume group ---
VG Name vg_cloud3
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 14.99 GiB
PE Size 4.00 MiB
Total PE 3838
Alloc PE / Size 1024 / 4.00 GiB
Free PE / Size 2814 / 10.99 GiB
VG UUID gFIuXV-UlJH-g2dH-bYin-VWdl-a4Qj-tZEHoP
[root@lvm ~]# lvscan
ACTIVE '/dev/centos/swap' [2.00 GiB] inherit
ACTIVE '/dev/centos/root' [<17.00 GiB] inherit
ACTIVE '/dev/vg_cloud3/cloud3' [4.00 GiB] inherit
[root@lvm ~]# lvextend -L +5G /dev/vg_cloud3/cloud3
Size of logical volume vg_cloud3/cloud3 changed from 4.00 GiB (1024 extents) to 9.00 G iB (2304 extents).
Logical volume vg_cloud3/cloud3 successfully resized.
[root@lvm ~]# lvscan
ACTIVE '/dev/centos/swap' [2.00 GiB] inherit
ACTIVE '/dev/centos/root' [<17.00 GiB] inherit
ACTIVE '/dev/vg_cloud3/cloud3' [9.00 GiB] inherit
[root@lvm ~]# resize2fs /dev/vg_cloud3/cloud3
resize2fs 1.42.9 (28-Dec-2013)
Filesystem at /dev/vg_cloud3/cloud3 is mounted on /root/backup; on-line resizing requi red
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/vg_cloud3/cloud3 is now 2359296 blocks long.
[root@lvm ~]# df -hT
文件系统 类型 容量 已用 可用 已用% 挂载点
/dev/mapper/centos-root xfs 17G 10G 7.1G 59% /
devtmpfs devtmpfs 473M 0 473M 0% /dev
tmpfs tmpfs 489M 0 489M 0% /dev/shm
tmpfs tmpfs 489M 14M 475M 3% /run
tmpfs tmpfs 489M 0 489M 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 161M 854M 16% /boot
tmpfs tmpfs 98M 8.0K 98M 1% /run/user/42
tmpfs tmpfs 98M 24K 98M 1% /run/user/1000
tmpfs tmpfs 98M 0 98M 0% /run/user/0
/dev/mapper/vg_cloud3-cloud3 ext4 8.8G 9.0M 8.4G 1% /root/backup
