PV(physical volume)：物理卷在逻辑卷管理系统最底层，可为整个物理硬盘或实际物理硬盘上的分区。
VG(volume group)：卷组建立在物理卷上，一卷组中至少要包括一物理卷，卷组建立后可动态的添加卷到卷组中，一个逻辑卷管理系统工程中可有多个卷组。
LV(logical volume)：逻辑卷建立在卷组基础上，卷组中未分配空间可用于建立新的逻辑卷，逻辑卷建立后可以动态扩展和缩小空间。
不同的物理卷可以构成卷组，逻辑卷则是对卷组进行详细的划分，一个卷组可划分为多个逻辑卷。
1.创建物理卷PV
[root@localhost ~]# pvcreate /dev/sda Physical volume "/dev/sda" successfully created. [root@localhost ~]# pvcreate /dev/nvme0n2 WARNING: dos signature detected on /dev/nvme0n2 at offset 510. Wipe it? [y/n]: y Wiping dos signature on /dev/nvme0n2. Physical volume "/dev/nvme0n2" successfully created.
[root@localhost ~]# pvs 查看物理卷信息 PV VG Fmt Attr PSize PFree /dev/nvme0n1p2 rhel lvm2 a-- <49.00g 0 /dev/nvme0n2 lvm2 --- 20.00g 20.00g /dev/sda lvm2 --- 5.00g 5.00g [root@localhost ~]# pvdisplay 查看更详细的物理卷信息
2.创建卷组VG
[root@localhost ~]# vgcreate vgname /dev/sda /dev/nvme0n2 //vgname表示所取得卷组名 Volume group "vgname" successfully created
[root@localhost ~]# vgs VG #PV #LV #SN Attr VSize VFree rhel 1 2 0 wz--n- <49.00g 0 vgname 2 0 0 wz--n- 24.99g 24.99g [root@localhost ~]# vgdisplay
3.创建逻辑卷LV（Logical Volumes）
-n表示逻辑卷取的名字 -L表示所分配的大小 vgname表示在vg为vgname上分配 //xfs不支持缩小
[root@localhost ~]# lvcreate -n lv1 -L 5G vgname WARNING: LVM2_member signature detected on /dev/vgname/lv1 at offset 536. Wipe it? [y/n]: y Wiping LVM2_member signature on /dev/vgname/lv1. Logical volume "lv1" created.
[root@localhost ~]# lvs LV VG Attr LSize Pool Origin Data% meta% Move Log Cpy%Sync Convert root rhel -wi-ao---- <45.06g swap rhel -wi-ao---- <3.94g lv1 vgname -wi-a----- 5.00g
查看LV信息
[root@localhost ~]# ll /dev/mapper/vgname-lv1 lrwxrwxrwx. 1 root root 7 Nov 23 06:51 /dev/mapper/vgname-lv1 -> ../dm-2 [root@localhost ~]# ll /dev/vgname/lv1 lrwxrwxrwx. 1 root root 7 Nov 23 06:51 /dev/vgname/lv1 -> ../dm-2
4.格式化逻辑卷lv1
[root@localhost ~]# mkfs.xfs /dev/mapper/vgname-lv1
meta-data=/dev/mapper/vgname-lv1 isize=512 agcount=4, agsize=327680 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=1310720, 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=0
5.挂载
[root@localhost /]# mkdir haha [root@localhost /]# mount /dev/mapper/vgname-lv1 /haha [root@localhost /]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 1.8G 0 1.8G 0% /dev tmpfs 1.9G 0 1.9G 0% /dev/shm tmpfs 1.9G 9.9M 1.9G 1% /run tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup /dev/mapper/rhel-root 46G 4.8G 41G 11% / /dev/nvme0n1p1 1014M 240M 775M 24% /boot tmpfs 371M 1.2M 370M 1% /run/user/42 tmpfs 371M 6.8M 365M 2% /run/user/0 /dev/sr0 8.9G 8.9G 0 100% /run/media/root/RHEL-8-3-0-baseOS-x86_64 /dev/mapper/vgname-lv1 5.0G 68M 5.0G 2% /haha删除lvm步骤
1.取消挂载
[root@localhost /]# umount /dev/mapper/vgname-lv1
2.删除LV
[root@localhost /]# lvremove /dev/vgname/lv1 Do you really want to remove active logical volume vgname/lv1? [y/n]: y Logical volume "lv1" successfully removed
3.删除VG
[root@localhost /]# vgremove vgname Volume group "vgname" successfully removed
4.删除PV
[root@localhost /]# pvremove /dev/sda Labels on physical volume "/dev/sda" successfully wiped. [root@localhost /]# pvremove /dev/nvme0n2 Labels on physical volume "/dev/nvme0n2" successfully wiped.
注意：lvm进行分区时 xfs文件不支持缩小
