KVM ---- 虚拟磁盘扩容

磁盘不够使用，添加新的硬盘，或者扩容当前磁盘。

1、子机的当前磁盘状态

母机中查看该系统

[[email protected] ~]# qemu-img resize /caimz/caimz2.img +5G
Image resized.
[[email protected] ~]# qemu-img info /caimz/caimz2.img
image: /caimz/caimz2.img
file format: raw
virtual size: 35G (37580963840 bytes)
disk size: 30G

[[email protected] ~]# virsh start caimz2 --console
error: Domain is already active

[[email protected] ~]#
[[email protected] ~]# virsh start caimz2 --console
error: Domain is already active

操作步骤：

[[email protected] ~]# fdisk -l

Disk /dev/vda: 37.6 GB, 37580963840 bytes
16 heads, 63 sectors/track, 72817 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0004583c

Device Boot      Start         End      Blocks   Id System
/dev/vda1   *           3        1018      512000   83 Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2            1018       62416    30944256   8e Linux LVM
Partition 2 does not end on cylinder boundary.

Disk /dev/mapper/VolGroup-lv_root: 30.6 GB, 30610030592 bytes
255 heads, 63 sectors/track, 3721 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

[[email protected] ~]# df -h
Filesystem            Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       28G 720M   26G   3% /
tmpfs                 250M     0 250M   0% /dev/shm
/dev/vda1             477M   31M 421M   7% /boot
[[email protected] ~]# fdisk -l

[[email protected] ~]# fdisk /dev/vda

WARNING: DOS-compatible mode is deprecated. It‘s strongly recommended to
switch off the mode (command ‘c‘) and change display units to
sectors (command ‘u‘).

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (1-72817, default 1): 62417
Last cylinder, +cylinders or +size{K,M,G} (62416-72817, default 72817): 72817

Command (m for help): p

Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 4
First cylinder (1-72817, default 1): 62417 #inode 在/dev/vda2 都是62416 所以应从62417开始
Last cylinder, +cylinders or +size{K,M,G} (62417-72817, default 72817): 72817#结束

Command (m for help): p

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.
[[email protected] ~]# fdisk -l

创建物理卷

然后再把这个/dev/vda4 加入到lvm里面去：

ls /dev/vda4 如果没有这个分区，需要重启一下。

[[email protected] ~]# pvcreate /dev/vda4

Physical volume "/dev/vda4" successfully created

现在吧vda4加入到VolGroup里面

[[email protected] ~]# vgextend VolGroup /dev/vda4
Volume group "VolGroup" successfully extended

查看vda4是不是属于VolGroup组里面。

[[email protected] ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup 2 2 0 wz--n- 34.50g 5.00g

看逻辑卷

[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_root VolGroup -wi-ao---- 28.51g
lv_swap VolGroup -wi-ao---- 1.00g

现在要把之前添加的5G 加到lv_root里面

[[email protected] ~]# lvextend -l +100%FREE /dev/VolGroup/lv_root
Size of logical volume VolGroup/lv_root changed from 28.51 GiB (7298 extents) to 33.50 GiB (8577 extents).
Logical volume lv_root successfully resized
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_root VolGroup -wi-ao---- 33.50g

lv_swap VolGroup -wi-ao---- 1.00g