虚拟机两个组成部分，镜像文件和xml 配置声明文件
1.根据后端盘做一个镜像文件
[root@xq images]# qemu-img create -f qcow2 -b xq.qcow2 xq.img 20G
2.cp一个虚拟机配置声明文件
[root@xq~]# cp node.xml /etc/libvirt/qemu/xq.xml
1 <!-- 2 WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE 3 OVERWRITTEN AND LOST. Changes to this xml configuration should be made using: 4 virsh edit xq 5 or other application using the libvirt API. 6 --> 7 8 <domain type='kvm'> 9 <name>xq</name> 10 <uuid>1b559fbd-ecf1-41cf-8426-0a39af30a640</uuid> 11 <memory unit='KiB'>1488282</memory> 12 <currentMemory unit='KiB'>1488282</currentMemory> 13 <vcpu placement='static'>2</vcpu> 14 <os> 15 <type arch='x86_64' machine='pc-i440fx-rhel7.0.0'>hvm</type> 16 <boot dev='hd'/> 17 <bootmenu enable='yes'/> 18 <bios useserial='yes'/> 19 </os> 20 <features> 21 <acpi/> 22 <apic/> 23 </features> 24 <cpu mode='host-passthrough' check='none'/> 25 <clock offset='localtime'/> 26 <on_poweroff>destroy</on_poweroff> 27 <on_reboot>restart</on_reboot> 28 <on_crash>restart</on_crash> 29 <devices> 30 <emulator>/usr/libexec/qemu-kvm</emulator> 31 <disk type='file' device='disk'> 32 <driver name='qemu' type='qcow2'/> 33 <source file='/var/lib/libvirt/images/xq.img'/> 34 <target dev='vda' bus='virtio'/> 35 <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> 36 </disk> 37 <controller type='usb' index='0' model='piix3-uhci'> 38 <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/> 39 </controller> 40 <controller type='pci' index='0' model='pci-root'/> 41 <controller type='virtio-serial' index='0'> 42 <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> 43 </controller> 44 <interface type='bridge'> 45 <mac address='52:54:00:a5:57:bb'/> 46 <source bridge='vbr'/> 47 <model type='virtio'/> 48 <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> 49 </interface> 50 <serial type='pty'> 51 <target port='0'/> 52 </serial> 53 <console type='pty'> 54 <target type='serial' port='0'/> 55 </console> 56 <channel type='unix'> 57 <target type='virtio' name='org.qemu.guest_agent.0'/> 58 <address type='virtio-serial' controller='0' bus='0' port='1'/> 59 </channel> 60 <input type='mouse' bus='ps2'/> 61 <input type='keyboard' bus='ps2'/> 62 <memballoon model='virtio'> 63 <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> 64 </memballoon> 65 </devices> 66 </domain>
[root@xq~]# virsh define /etc/libvirt/qemu/xq.xml
[root@xq~]#virsh start xq
[root@xq~]#ssh 192.168.1.154
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/vda1 2.0G 1.1G 995M 52% /
devtmpfs 698M 0 698M 0% /dev
tmpfs 708M 0 708M 0% /dev/shm
tmpfs 708M 17M 691M 3% /run
tmpfs 708M 0 708M 0% /sys/fs/cgroup
tmpfs 142M 0 142M 0% /run/user/0
[root@localhost ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 253:0 0 20G 0 disk
└─vda1 253:1 0 2G 0 part /
[root@localhost ~]# growpart /dev/vda 1
unexpected output in sfdisk --version [sfdisk，来自 util-linux 2.23.2]
解决办法：定义全局变量，语言改为英文 （编码）
export LANG=en_US.UTF-8export LANG=en_US.UTF-8
语言可以用 echo $LANG查看(locale查语言类型）
en_US.UTF-8
[root@localhost ~]# growpart /dev/vda 1
CHANGED: partition=1 start=2048 old: size=4192256 end=4194304 new: size=41940959,end=41943007
[root@localhost~]# xfs_growfs /
最后使用lsblk和df -h 查看磁盘情况
扩容问题就ok了
扩容问题也是弹性云主机的奥秘所在（通过已有资源，自己分配磁盘大小）
改完编码还不可以试试重启机子