lvm机制的基本概念
- PV （physicak volume 物理卷）
处于LVM最底层，可以是整个硬盘或使用fdisk等工具建立的普通分区
包括许多默认4MB大小的PE，PE是PV中可以用于分配的最小存储单元- VG（volume group 卷组）
是一个或多个物理卷组合而成的整体，建立在PV之上的。
同一VG中所以PV的PE大小应该相同，当VG被创建后，我们才能正常查看PE数量- LV（logical volume ，逻辑卷）
从卷组中分割出的一块空间，他是建立在VG之上，相当于原来分区的概念。不过大小可以动态改变。其实LV就是由PE组成的，不过在LV里面这些PE叫做LE
LE(Logical extents)是LV中可以用于分配的最小存储单元，与PE大小相同并一一对应1. 对vdc进行lvm的分区
推荐步骤：添加硬盘——>分区8e——>PV——>VG——>LV——>格式化——>挂载使用文件系统
——>修改系统挂载文件，设置开机挂载1.1 查看当前机器分区状态
$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 50G 1.2G 49G 3% /
devtmpfs devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs tmpfs 1.9G 8.4M 1.9G 1% /run
tmpfs tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 143M 872M 15% /boot
/dev/mapper/centos-home xfs 26G 33M 26G 1% /home
tmpfs tmpfs 380M 0 380M 0% /run/user/0
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
sr0 11:0 1 1024M 0 rom1.2 进行分区
分一个主分区，将全部都分给主分区
$ fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).
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 0x969372a9.
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition s system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519):
Using default value 20971519
Partition 1 of type Linux and of size 10 GiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sr0 11:0 1 1024M 0 rom1.3 创建物理卷
$ pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created.1.4 创建卷组vgdata
$ vgcreate vgdata /dev/sdb1
Volume group "vgdata" successfully created1.5 创建逻辑卷
$ lvcreate -n lvdata vgdata -l 100%VG
Logical volume "lvdata" created.1.6 初始化xfs类型的文件系统
$ mkfs.xfs /dev/vgdata/lvdata
meta-data=/dev/vgdata/lvdata isize=512 agcount=4, agsize=655104 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=2620416, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=01.7 挂载文件系统到目录
$ mount /dev/vgdata/lvdata /pkl_test
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─vgdata-lvdata 253:3 0 10G 0 lvm /pkl_test
sr0 11:0 1 1024M 0 rom
$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 50G 1.2G 49G 3% /
devtmpfs devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs tmpfs 1.9G 8.4M 1.9G 1% /run
tmpfs tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 143M 872M 15% /boot
/dev/mapper/centos-home xfs 26G 33M 26G 1% /home
tmpfs tmpfs 380M 0 380M 0% /run/user/0
/dev/mapper/vgdata-lvdata xfs 10G 33M 10G 1% /pkl_test1.8 将挂盘写进系统启动的初始化文件里面（/etc/fstab）
$ cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Mon Jul 4 19:58:25 2016
#
# 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/vda1 / xfs defaults 0 1
/swapfile none swap defaults 0 0
/dev/vdb /data xfs defaults,noatime 0 0
/dev/mapper/vgdata-lvdata /pkl_test xfs defaults 0 0之后，再重启的时候，盘也会一直挂载系统上了。
2.在线扩容
不需要重启。
2.1 新加一个盘
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─vgdata-lvdata 253:3 0 10G 0 lvm /pkl_test
sdc 8:32 0 8G 0 disk
sr0 11:0 1 1024M 0 rom2.2 创建为物理卷（pv）
$ pvcreate /dev/sdc
Physical volume "/dev/sdc" successfully created.
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─vgdata-lvdata 253:3 0 10G 0 lvm /pkl_test
sdc 8:32 0 8G 0 disk
sr0 11:0 1 1024M 0 rom2.3 当前系统的物理卷（pv）和卷组（vg）
$ pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <79.00g 4.00m
/dev/sdb1 vgdata lvm2 a-- <10.00g 0
/dev/sdc lvm2 --- 8.00g 8.00g
$ vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 3 0 wz--n- <79.00g 4.00m
vgdata 1 1 0 wz--n- <10.00g 02.4 卷组vgdata扩容
将物理卷/dev/sdc扩展至vgdata卷组
$ vgextend vgdata /dev/sdc
Volume group "vgdata" successfully extended2.5 更改后vg和当前lg的情况
$ vgdisplay
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 1
Act PV 1
VG Size <79.00 GiB
PE Size 4.00 MiB
Total PE 20223
Alloc PE / Size 20222 / 78.99 GiB
Free PE / Size 1 / 4.00 MiB
VG UUID 33hOTD-jjk1-kb4b-sRdZ-uBmN-ujSt-7wQhbQ
--- Volume group ---
VG Name vgdata
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
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 17.99 GiB
PE Size 4.00 MiB
Total PE 4606
Alloc PE / Size 2559 / <10.00 GiB
Free PE / Size 2047 / <8.00 GiB
VG UUID iYEoGE-s2hq-fbpN-Oy7F-mHSu-uSjn-2TGJDt
$ lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID iLjbZC-4g7F-dkC8-eZyb-uCGx-aZo1-VMptq4
LV Write Access read/write
LV Creation host, time localhost, 2021-04-28 19:50:06 +0800
LV Status available
# open 2
LV Size <3.88 GiB
Current LE 992
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/centos/home
LV Name home
VG Name centos
LV UUID DKhvbr-gt8n-idlm-s9f2-YiYN-k3Vj-LYvpwU
LV Write Access read/write
LV Creation host, time localhost, 2021-04-28 19:50:06 +0800
LV Status available
# open 1
LV Size <25.12 GiB
Current LE 6430
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
--- Logical volume ---
LV Path /dev/centos/root
LV Name root
VG Name centos
LV UUID WzSvke-Oeci-UyGx-djsV-PO9P-R2VE-faF2lZ
LV Write Access read/write
LV Creation host, time localhost, 2021-04-28 19:50:07 +0800
LV Status available
# open 1
LV Size 50.00 GiB
Current LE 12800
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
--- Logical volume ---
LV Path /dev/vgdata/lvdata
LV Name lvdata
VG Name vgdata
LV UUID 1TjhlL-K5wH-rce3-cqyt-EN7S-TE0c-v0ry9r
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2021-05-12 11:10:15 +0800
LV Status available
# open 1
LV Size <10.00 GiB
Current LE 2559
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:32.6 lvdata扩容
如果直接+10G上限会报错，最好加的少点+9.8G就可以，演示的例子做了很多测试，正式可以直接加。
$ lvextend -L +10G /dev/vgdata/lvdata # 报错
Insufficient free space: 2560 extents needed, but only 1407 available
$ lvextend -L +5.5G /dev/vgdata/lvdata
Insufficient free space: 1408 extents needed, but only 1407 available
$ lvextend -L +5G /dev/vgdata/lvdata
Size of logical volume vgdata/lvdata changed from <12.50 GiB (3199 extents) to <17.50 GiB (4479 extents).
Logical volume vgdata/lvdata successfully resized.
$ lvextend -L +0.4G /dev/vgdata/lvdata
Rounding size to boundary between physical extents: 412.00 MiB.
Size of logical volume vgdata/lvdata changed from <17.50 GiB (4479 extents) to <17.90 GiB (4582 extents).
Logical volume vgdata/lvdata successfully resized.查看当前分区情况
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─vgdata-lvdata 253:3 0 17.9G 0 lvm /pkl_test
sdc 8:32 0 8G 0 disk
└─vgdata-lvdata 253:3 0 17.9G 0 lvm /pkl_test
sr0 11:0 1 1024M 0 rom2.7 空间合并
$ xfs_growfs /dev/vgdata/lvdata
meta-data=/dev/mapper/vgdata-lvdata isize=512 agcount=4, agsize=655104 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=2620416, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 2620416 to 4691968ext4文件系统需要用这个命令扩盘：
$ resize2fs /dev/centos/root2.8 lvm动态扩容是否成功
$ df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 50G 1.2G 49G 3% /
devtmpfs devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs tmpfs 1.9G 8.4M 1.9G 1% /run
tmpfs tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 143M 872M 15% /boot
/dev/mapper/centos-home xfs 26G 33M 26G 1% /home
/dev/mapper/vgdata-lvdata xfs 18G 33M 18G 1% /pkl_test
tmpfs tmpfs 380M 0 380M 0% /run/user/0
$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 80G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 79G 0 part
├─centos-root 253:0 0 50G 0 lvm /
├─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
└─centos-home 253:2 0 25.1G 0 lvm /home
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
└─vgdata-lvdata 253:3 0 17.9G 0 lvm /pkl_test
sdc 8:32 0 8G 0 disk
└─vgdata-lvdata 253:3 0 17.9G 0 lvm /pkl_test
sr0 11:0 1 1024M 0 rom按照以前文档的说法，系统的重启后读取的初始化文件可不动。即，不用修改/etc/fstab，重启也是生效的。
3. 删除lvm分区
lvm分区 （千万不要在没有关闭LVM的情况下删除分区）
- umount卸载lvm文件系统
umount /dev/mapper/vgdata-lvdata- lvremove删除逻辑卷
lvremove vgdata- vgremove删除卷组
vgremove vgdata- pvremove删除物理卷
pvremove /dev/sdb1- 清楚/etc/fstab中的lvm挂载记录
- fdisk修改分区ID
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