partprobe /dev/sdb 此命令在磁盘分区作用是刷新磁盘分区表
指定PE大小的参数 vgcreate xcloudvg /dev/sdb[1-2] -s 16M PE 的大小，单位可以是 MB、GB、TB 等，如果不写，则默认 PE 大小是 4MB
实验一
使用 xserver1 虚拟机，使用 VMWare 软件自行添加一块大小为 20G 的硬盘，使用 fdisk 命令对该硬盘进行分区，要求分出三个大小为 5G 的分区。使用这三个分区，创建名 xcloudvg 的逻辑卷，大小为 12G ，最后用 ext4 文件系统对逻辑卷进行格式化并挂载带 /mnt 目录下。
添加磁盘 20G
[root@xserver1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 40G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 39.5G 0 part
├─centos-root 253:0 0 35.6G 0 lvm /
└─centos-swap 253:1 0 3.9G 0 lvm [SWAP]
sdb 8:16 0 20G 0 disk
sr0 11:0 1 1024M 0 rom
分区
[root@xserver1 ~]# 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 0x7905fea8.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1):
First sector (2048-41943039, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +5G
Partition 1 of type Linux and of size 5 GiB is set
Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p):
Using default response p
Partition number (2-4, default 2):
First sector (10487808-41943039, default 10487808):
Using default value 10487808
Last sector, +sectors or +size{K,M,G} (10487808-41943039, default 41943039): +5G
Partition 2 of type Linux and of size 5 GiB is set
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p):
Using default response p
Partition number (3,4, default 3):
First sector (20973568-41943039, default 20973568):
Using default value 20973568
Last sector, +sectors or +size{K,M,G} (20973568-41943039, default 41943039): +5G
Partition 3 of type Linux and of size 5 GiB is set
Command (m for help): p #查看
Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x7905fea8
Device Boot Start End Blocks Id System
/dev/sdb1 2048 10487807 5242880 83 Linux
/dev/sdb2 10487808 20973567 5242880 83 Linux
/dev/sdb3 20973568 31459327 5242880 83 Linux
