當前物理機OS爲RHEL7.2
本篇文章使用的是物理上的塊設備（邏輯卷）來建立kvm虛擬機。這樣比使用文件來建立虛擬機的效率要高的多
step1：準備工作
當前物理機的網絡配置爲：物理機有一個網卡em1，我創建了一個網橋br0，用來作爲虛擬機連接到物理機的橋接通道
[root@file qemu]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.549f35121014 no em1
virbr0 8000.52540002a17b yes virbr0-nic
br0用於橋接到物理網卡
virbr0用於做NAT
注意：br0需要你自己添加，virbr0不需要，系統自帶的
[root@file network-scripts]# more ifcfg-br0
BOOTPROTO=static
#DEVICE=virbr0
DEVICE=br0
ONBOOT=yes
TYPE=Bridge ##類型是bridge
NAME=br0
IPADDR=192.168.107.105
NETMASK=255.255.255.0
GATEWAY=192.168.107.1
DEFROUTE=yes
[root@file network-scripts]# more ifcfg-em1
# Generated by parse-kickstart
BOOTPROTO=none
DEVICE=em1
ONBOOT=yes
UUID=9244d816-622e-41e5-a357-3ca0f00e8ad5
TYPE=Ethernet
NAME=em1
NM_CONTROLLED=no ##該網卡不在NetworkManager服務的管理下，並且之後關閉該服務。
#IPADDR=192.168.107.105
#NETMASK=255.255.255.0
#GATEWAY=192.168.107.1
BRIDGE=br0 ##em1網卡橋接到br0
注意：需要將NetworkManager 關閉掉纔可以，如果不關的話可能會導致物理機無法ping通虛擬機
systemctl stop NetworkManager
systemctl disable NetworkManager
systemctl is-enable NetworkManager
查看存儲池的配置：
[root@file ~]# virsh pool-info storage1 ##這裏的storage1 存儲池是我之前在virt-manager圖形界面建立的
Name: storage1
UUID: 3aacbac0-07ec-4c3d-b5ae-d33a4b980279
State: running
Persistent: yes
Autostart: yes
Capacity: 930.69 GiB
Allocation: 238.00 GiB
Available: 692.69 GiB
創建用於安裝虛擬機的lvm
[root@file ~]# lvcreate -L 20G -n rhel7.2_test server
Logical volume "rhel7.2_test" created.
[root@file ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
rhel7.2_oracle server -wi-ao---- 60.00g
rhel7.2_test server -wi-a----- 20.00g
root server -wi-ao---- 20.00g
storage server -wi-ao---- 100.00g
swap server -wi-ao---- 8.00g
u01 server -wi-ao---- 50.00g
[root@file ~]# mkfs.xfs /dev/mapper/server-rhel7.2_test
必須格式化，不然在創建虛擬機的時候看不到卷，就無法使用卷
step2：新建虛擬機，採用NAT方式連接
virt-manager-->新建虛擬機
左側的storage1是新建的storage pool，右側的rhel7.2_test卷是上邊lvcreate創建的，如果之前不格式化的話，在這裏看不到該卷
選擇rhel7.2_test卷作爲這次虛擬機安裝的存儲設備
在網絡這裏選擇NAT方式連接
給這臺虛擬機配置個名字
之後就是虛擬機安裝過程了，分區如下，其他步驟就不截屏了
附：當前物理機及虛擬機的網絡配置
1 橋接方式
我的第一臺虛擬機使用的是橋接方式，配置如下：
2 NAT方式
我這裏新建的虛擬機是NAT方式連接，配置如下：
此時物理機的ip如下
[root@file ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: em1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master br0 state UP qlen 1000
link/ether 54:9f:35:12:10:14 brd ff:ff:ff:ff:ff:ff
inet6 fe80::569f:35ff:fe12:1014/64 scope link
valid_lft forever preferred_lft forever
3: em2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 54:9f:35:12:10:15 brd ff:ff:ff:ff:ff:ff
4: em3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 54:9f:35:12:10:16 brd ff:ff:ff:ff:ff:ff
5: em4: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
link/ether 54:9f:35:12:10:17 brd ff:ff:ff:ff:ff:ff
6: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
link/ether 54:9f:35:12:10:14 brd ff:ff:ff:ff:ff:ff
inet 192.168.107.105/24 brd 192.168.107.255 scope global br0
valid_lft forever preferred_lft forever
inet6 fe80::569f:35ff:fe12:1014/64 scope link
valid_lft forever preferred_lft forever
7: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP
link/ether 52:54:00:02:a1:7b brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
8: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN qlen 500
link/ether 52:54:00:02:a1:7b brd ff:ff:ff:ff:ff:ff
9: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UNKNOWN qlen 500
link/ether fe:54:00:0b:6e:99 brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc54:ff:fe0b:6e99/64 scope link
valid_lft forever preferred_lft forever
11: vnet1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master virbr0 state UNKNOWN qlen 500
link/ether fe:54:00:f9:51:af brd ff:ff:ff:ff:ff:ff
inet6 fe80::fc54:ff:fef9:51af/64 scope link
valid_lft forever preferred_lft forever
新安裝的nat網絡中的vm如下：
注：此圖是另外一臺nat虛擬機的信息，效果是一樣的，MAC不同
在主機上ping虛擬機ip
[root@file ~]# ping 192.168.122.165
PING 192.168.122.165 (192.168.122.165) 56(84) bytes of data.
64 bytes from 192.168.122.165: icmp_seq=1 ttl=64 time=0.338 ms
64 bytes from 192.168.122.165: icmp_seq=2 ttl=64 time=0.322 ms
64 bytes from 192.168.122.165: icmp_seq=3 ttl=64 time=0.322 ms