现有基于KVM的数据库服务器系统盘40G，因需要新增40G数据盘进行分区扩容调整。
[root@SRV205 ~]# df -h #扩容前
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos_srv205-root 34G 3.8G 31G 11% /
devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 1.9G 8.9M 1.9G 1% /run
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda2 2.0G 145M 1.9G 8% /boot
tmpfs 379M 0 379M 0% /run/user/1000
[root@SRV205 ~]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x0004c40d
Device Boot Start End Blocks Id System
/dev/sda1 2048 6143 2048 83 Linux
/dev/sda2 * 6144 4200447 2097152 83 Linux
/dev/sda3 4200448 83886079 39842816 8e Linux LVM
Disk /dev/mapper/centos_srv205-root: 36.5 GB, 36503027712 bytes, 71294976 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_srv205-swap: 4294 MB, 4294967296 bytes, 8388608 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/sdb: 42.9 GB, 42949672960 bytes, 83886080 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@SRV205 ~]# fdisk /dev/sdb #加盘，格式创建新分区
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 0xe055cd83.
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):
First sector (2048-83886079, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-83886079, default 83886079):
Using default value 83886079
Partition 1 of type Linux and of size 40 GiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@SRV205 ~]# fdisk -l
Disk /dev/sda: 42.9 GB, 42949672960 bytes, 83886080 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: 0x0004c40d
Device Boot Start End Blocks Id System
/dev/sda1 2048 6143 2048 83 Linux
/dev/sda2 * 6144 4200447 2097152 83 Linux
/dev/sda3 4200448 83886079 39842816 8e Linux LVM
Disk /dev/mapper/centos_srv205-root: 36.5 GB, 36503027712 bytes, 71294976 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_srv205-swap: 4294 MB, 4294967296 bytes, 8388608 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/sdb: 42.9 GB, 42949672960 bytes, 83886080 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: 0xe055cd83
Device Boot Start End Blocks Id System
/dev/sdb1 2048 83886079 41942016 83 Linux
[root@SRV205 ~]# pvcreate /dev/sdb #将新增的分区创建一个物理卷，失败用-ff参数强制创建
Device /dev/sdb excluded by a filter.
[root@SRV205 ~]# lvs #查看vg名
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos_srv205 -wi-ao---- <34.00g
swap centos_srv205 -wi-ao---- 4.00g
[root@SRV205 ~]# vgextend centos_srv205 /dev/sdb1
Physical volume "/dev/sdb1" successfully created.
Volume group "centos_srv205" successfully extended
[root@SRV205 ~]# vgdisplay
--- Volume group ---
VG Name centos_srv205
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 77.99 GiB
PE Size 4.00 MiB
Total PE 19966
Alloc PE / Size 9727 / <38.00 GiB
Free PE / Size 10239 / <40.00 GiB
VG UUID s5K579-0ZtV-aiJJ-QAkE-x4Kp-Ejhn-kymXcj
[root@SRV205 mapper]# lvextend -l +100%FREE /dev/mapper/centos_srv205-root /dev/sdb1
Size of logical volume centos_srv205/root changed from <34.00 GiB (8703 extents) to 73.99 GiB (18942 extents).
Logical volume centos_srv205/root successfully resized.
[root@SRV205 mapper]# xfs_growfs /dev/mapper/centos_srv205-root
meta-data=/dev/mapper/centos_srv205-root isize=512 agcount=4, agsize=2227968 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=8911872, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=4351, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 8911872 to 19396608
[root@SRV205 mapper]# df -h #扩容后
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos_srv205-root 74G 3.8G 71G 6% /
devtmpfs 1.9G 0 1.9G 0% /dev
tmpfs 1.9G 0 1.9G 0% /dev/shm
tmpfs 1.9G 8.9M 1.9G 1% /run
tmpfs 1.9G 0 1.9G 0% /sys/fs/cgroup
/dev/sda2 2.0G 145M 1.9G 8% /boot
tmpfs 379M 0 379M 0% /run/user/1000