转自：https://blog.csdn.net/Wang_Xin_SH/article/details/77872885
简介 CentOS7虚拟机原硬盘空间只分配了10GB，需要扩容到20GB。 环境：VMware 10
VMware分配空间 选中虚拟机->虚拟机设置->硬盘->实用工具->扩展->设置最大磁盘大小->点击扩展 这里写图片描述
CentOS7内部分配 可以参考：http://jingyan.baidu.com/article/54b6b9c0fc8b0b2d583b47c6.html
查看当前磁盘空间，/dev/mapper/cl-root硬盘空间只有8GB，打算扩容：
df -h
Filesystem Size Used Avail Use% Mounted on /dev/mapper/cl-root 8.0G 3.8G 4.3G 47% / devtmpfs 482M 0 482M 0% /dev tmpfs 493M 0 493M 0% /dev/shm tmpfs 493M 6.7M 486M 2% /run tmpfs 493M 0 493M 0% /sys/fs/cgroup /dev/sda1 1014M 184M 831M 19% /boot tmpfs 99M 0 99M 0% /run/user/0 对新增的硬盘空间做新增分区（硬盘数没有增加，增加的是空间）
fdisk /dev/sda
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.
Command (m for help): n Partition type: p primary (2 primary, 0 extended, 2 free) e extended Select (default p): p Partition number (3,4, default 3): 3 First sector (20971520-41943039, default 20971520): Using default value 20971520 Last sector, +sectors or +size{K,M,G} (20971520-41943039, default 41943039): Using default value 41943039 Partition 3 of type Linux and of size 10 GiB is set
Command (m for help): t Partition number (1-3, default 3): 3 Hex code (type L to list all codes): 8e Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/sda: 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: 0x000bc924
Device Boot Start End Blocks Id System /dev/sda1 * 2048 2099199 1048576 83 Linux /dev/sda2 2099200 20971519 9436160 8e Linux LVM /dev/sda3 20971520 41943039 10485760 8e Linux LVM
Command (m for help): w The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot or after you run partprobe(8) or kpartx(8) Syncing disks. 重启系统 reboot 查看当前分区类型，本例类型为xfs
df -T /dev/sda1
Filesystem Type 1K-blocks Used Available Use% Mounted on /dev/sda1 xfs 1038336 188240 850096 19% /boot 1 2 3 在新磁盘上创建xfs文件系统
mkfs.xfs /dev/sda3
meta-data=/dev/sda3 isize=512 agcount=4, agsize=655360 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0, sparse=0 data = bsize=4096 blocks=2621440, 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 创建PV
pvcreate /dev/sda3
WARNING: xfs signature detected on /dev/sda3 at offset 0. Wipe it? [y/n]: y Wiping xfs signature on /dev/sda3. Physical volume "/dev/sda3" successfully created.
pvdisplay
--- Physical volume --- PV Name /dev/sda2 VG Name cl PV Size 9.00 GiB / not usable 3.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 2303 Free PE 0 Allocated PE 2303 PV UUID MlRwjY-TmVF-H8PV-heSz-ALGL-Q7sp-jFU6Al
"/dev/sda3" is a new physical volume of "10.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sda3
VG Name
PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 0hmgH0-0wVg-jWUW-65WX-1TYb-sUGH-6jF1qm
PV加入VG，vgextend后接VG Name，本例中为cl
vgdisplay
--- Volume group ---
VG Name cl
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 9.00 GiB
PE Size 4.00 MiB
Total PE 2303
Alloc PE / Size 2303 / 9.00 GiB
Free PE / Size 0 / 0
VG UUID dYdb4l-wMUh-e2xv-WiaJ-Oa52-NvdF-s5ICJC
vgextend cl /dev/sda3
VG加入LV
lvextend -l +2559 /dev/cl/root
Size of logical volume cl/root changed from 8.00 GiB (2047 extents) to 17.99 GiB (4606 extents). Logical volume cl/root successfully resized. 后两个参数“+2559”和“/dev/cl/root”来源详解： “+2559”来自于vgdisplay命令的Free PE/Size字段
vgdisplay
--- Volume group --- VG Name cl ... VG Size 18.99 GiB PE Size 4.00 MiB Total PE 4862 Alloc PE / Size 2303 / 9.00 GiB Free PE / Size 2559 / 10.00 GiB VG UUID dYdb4l-wMUh-e2xv-WiaJ-Oa52-NvdF-s5ICJC “/dev/cl/root”来自于lvdisplay命令的LV Path字段。
lvdisplay
... --- Logical volume --- LV Path /dev/cl/root ... 调整文件系统大小，本例中是xfs文件系统使用xfs_growfs命令调整，若其他文件系统，如ext4使用resize2fs命令，注意区分。
xfs_growfs /dev/cl/root
meta-data=/dev/mapper/cl-root isize=512 agcount=4, agsize=524032 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=0 spinodes=0 data = bsize=4096 blocks=2096128, 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 2096128 to 4716544 结果 /dev/mapper/cl-root从8G增加到了18G
df -h
Filesystem Size Used Avail Use% Mounted on /dev/mapper/cl-root 18G 3.8G 15G 21% / devtmpfs 482M 0 482M 0% /dev tmpfs 493M 0 493M 0% /dev/shm tmpfs 493M 6.7M 486M 2% /run tmpfs 493M 0 493M 0% /sys/fs/cgroup /dev/sda1 1014M 184M 831M 19% /boot tmpfs 99M 0 99M 0% /run/user/0
