LVM 磁盘空间扩容
查看分区情况
[root@localhost ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000d0c42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
Disk /dev/mapper/centos-root: 18.2 GB, 18249416704 bytes, 35643392 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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
可以看到磁盘已经扩展到53.7GB，但是还不能使用。
开始分区
[root@localhost ~]# fdisk -l /dev/sda
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000d0c42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
[root@localhost ~]# fdisk /dev/sda2
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 0x213fc3e8.
Command (m for help): q
[root@localhost ~]# 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): m # 备注：查看帮助信息
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): p # 备注：查看当前分区表
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000d0c42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
Command (m for help): n # 备注：新建分区表
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p): p # 备注：选择主分区
Partition number (3,4, default 3): # 备注：保持默认
First sector (41943040-104857599, default 41943040): # 备注：提示修改大小，保持默认
Using default value 41943040
Last sector, +sectors or +size{K,M,G} (41943040-104857599, default 104857599): # 备注：提示修改大小，保持默认
Using default value 104857599
Partition 3 of type Linux and of size 30 GiB is set
Command (m for help): t # 备注：修改分区id
Partition number (1-3, default 3): 3 # 备注： 选择分3
Hex code (type L to list all codes): L # 查看所有可用的分区编码，我们使用8e
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx
5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data
6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility
8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt
9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access
a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f2 DOS secondary
16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT
1e Hidden W95 FAT1 80 Old Minix
Hex code (type L to list all codes): 8e # 备注：输入分区编码8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): w # 备注：保存
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.
[root@localhost ~]#
再次查看分区情况：
[root@localhost ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000d0c42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
/dev/sda3 41943040 104857599 31457280 8e Linux LVM
Disk /dev/mapper/centos-root: 18.2 GB, 18249416704 bytes, 35643392 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 17G 1.6G 16G 10% /
devtmpfs 908M 0 908M 0% /dev
tmpfs 920M 0 920M 0% /dev/shm
tmpfs 920M 8.5M 911M 1% /run
tmpfs 920M 0 920M 0% /sys/fs/cgroup
/dev/sda1 1014M 145M 870M 15% /boot
tmpfs 184M 0 184M 0% /run/user/0
为了不重启虚拟机，使用partprobe命令使配置生效：
[root@localhost ~]# partprobe
[root@localhost ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 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: 0x000d0c42
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
/dev/sda3 41943040 104857599 31457280 8e Linux LVM
Disk /dev/mapper/centos-root: 18.2 GB, 18249416704 bytes, 35643392 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 /dev/mapper/centos-swap: 2147 MB, 2147483648 bytes, 4194304 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
可以看到新的分区/dev/sda3已经标记为Linux LVM，如果没有需要reboot或者partprobe。
调整LVM大小
查看当前LVM信息
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name centos # 备注：注意关注此行
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 <19.00 GiB
PE Size 4.00 MiB
Total PE 4863
Alloc PE / Size 4863 / <19.00 GiB
Free PE / Size 0 / 0
VG UUID IaHi9d-Q4Ia-WBrL-WFqd-sv9S-a5o3-SjHNkc
centos是我的VolumeGroup的名称，实际操作时，需要使用实际显示的名称。
创建物理卷并进行扩展LVM
把新分区的空间创建一个新的物理卷：
# 创建物理卷
[root@localhost ~]# pvcreate /dev/sda3
Physical volume "/dev/sda3" successfully created.
# 扩展LVM的VolumeGroup
[root@localhost ~]# vgextend centos /dev/sda3
Volume group "centos" successfully extended
# 扩展LVM的逻辑卷
[root@localhost ~]# lvextend /dev/mapper/centos-root /dev/sda3
Size of logical volume centos/root changed from <17.00 GiB (4351 extents) to 46.99 GiB (12030 extents).
Logical volume centos/root successfully resized.
# 调整逻辑卷大小
[root@localhost ~]# resize2fs /dev/mapper/centos-root
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/centos-root
Couldn't find valid filesystem superblock.
可以发现调整逻辑卷大小失败：
[root@localhost ~]# resize2fs /dev/mapper/centos-root
resize2fs 1.42.9 (28-Dec-2013)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/centos-root
Couldn't find valid filesystem superblock.
# 查看文件格式，发现/dev/mapper/centos-root是xfs格式的
[root@localhost ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 17G 1.6G 16G 10% /
devtmpfs devtmpfs 908M 0 908M 0% /dev
tmpfs tmpfs 920M 0 920M 0% /dev/shm
tmpfs tmpfs 920M 8.5M 911M 1% /run
tmpfs tmpfs 920M 0 920M 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 145M 870M 15% /boot
tmpfs tmpfs 184M 0 184M 0% /run/user/0
# xfs格式的文件扩充需要使用 xfs_growfs
[root@localhost ~]# xfs_growfs /dev/mapper/centos-root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=1113856 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=4455424, 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 4455424 to 12318720
# 查看修改后的效果
[root@localhost ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 47G 1.6G 46G 4% /
devtmpfs devtmpfs 908M 0 908M 0% /dev
tmpfs tmpfs 920M 0 920M 0% /dev/shm
tmpfs tmpfs 920M 8.5M 911M 1% /run
tmpfs tmpfs 920M 0 920M 0% /sys/fs/cgroup
/dev/sda1 xfs 1014M 145M 870M 15% /boot
tmpfs tmpfs 184M 0 184M 0% /run/user/0
可以看到虚拟机的磁盘大小已经调整成功。