centos8 下安装kvm虚拟机

kvm虚拟机安装步骤

步骤一： 检查系统配置

测试系统是否支持虚拟机话，不行的话要再bios中设置 虚拟化

[[email protected] ~]# lscpu
Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              2
On-line CPU(s) list: 0,1
Thread(s) per core:  1
Core(s) per socket:  2
Socket(s):           1
NUMA node(s):        1
Vendor ID:           AuthenticAMD
CPU family:          16
Model:               4
Model name:          AMD Phenom(tm) II X2 B57 Processor
Stepping:            3
CPU MHz:             3200.000
CPU max MHz:         3200.0000
CPU min MHz:         800.0000
BogoMIPS:            6429.41
Virtualization:      AMD-V
L1d cache:           64K
L1i cache:           64K
L2 cache:            512K
L3 cache:            6144K
NUMA node0 CPU(s):   0,1
Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc cpuid extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt hw_pstate vmmcall npt lbrv svm_lock nrip_save

可以看到 本机器支持虚拟化  Virtualization:      AMD-V

如果没有相应的输出，就需要到bios设定或者是系统不支持。

确认有无kvm模块

[[email protected] ~]#  modprobe kvm
[[email protected] ~]# lsmod |grep kvm
kvm_amd               110592  0
ccp                    98304  1 kvm_amd
kvm                   786432  1 kvm_amd
irqbypass              16384  1 kvm

步骤二： 安装支撑包

确认系统已经安装好yum，网络通畅。

然后安装kvm虚拟机的安装包

# yum install qemu-kvm libvert virt-install -y

步骤三：安装centos虚拟机，我们采用centos7.8 minimal镜像，命令行启动

virt-install --name=centos7 --memory=512,maxmemory=1980  --vcpus=2,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/root/CentOS-7-x86_64-DVD-1708.iso --disk path=/vms/centos7.qcow2,size=80 --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args=“console=tty0 console=ttyS0”

错误信息如下：

[[email protected] ~]# virt-install --name=centos7 --memory=1980,maxmemory=1980  --vcpus=2,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/root/CentOS-7-x86_64-Minimal-2003.iso --disk path=/vms/centos7.qcow2,size=80 --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args="console=tty0 console=ttyS0"
WARNING  The requested volume capacity will exceed the available pool space when the volume is fully allocated. (81920 M requested capacity > 47670 M available)
WARNING  OS name 'rhel7' is deprecated, using 'rhel7.0' instead. This alias will be removed in the future.
WARNING  /root/CentOS-7-x86_64-Minimal-2003.iso may not be accessible by the hypervisor. You will need to grant the 'qemu' user search permissions for the following directories: ['/root']
ERROR    The requested volume capacity will exceed the available pool space when the volume is fully allocated. (81920 M requested capacity > 47670 M available) (Use --check disk_size=off or --check all=off to override)

 这里出现了2个错误，一个是space空间问题，一个是qemu user的问题

解决：

增加 --connect参数

[[email protected] ~]# virt-install --name=centos7 --memory=1980,maxmemory=1980  --vcpus=2,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/root/CentOS-7-x86_64-Minimal-2003.iso --disk path=/vms/centos7.qcow2,size=80 --connect qemu:///system  --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args="console=tty0 console=ttyS0"
WARNING  The requested volume capacity will exceed the available pool space when the volume is fully allocated. (81920 M requested capacity > 47670 M available)
WARNING  OS name 'rhel7' is deprecated, using 'rhel7.0' instead. This alias will be removed in the future.
WARNING  /root/CentOS-7-x86_64-Minimal-2003.iso may not be accessible by the hypervisor. You will need to grant the 'qemu' user search permissions for the following directories: ['/root']
ERROR    The requested volume capacity will exceed the available pool space when the volume is fully allocated. (81920 M requested capacity > 47670 M available) (Use --check disk_size=off or --check all=off to override)

 将虚拟机的硬盘大小调整到40G

[[email protected] ~]# virt-install --name=centos7 --memory=1980,maxmemory=1980  --vcpus=2,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/root/CentOS-7-x86_64-Minimal-2003.iso --disk path=/vms/centos7.qcow2,size=40 --connect qemu:///system  --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args="console=tty0 console=ttyS0"
WARNING  OS name 'rhel7' is deprecated, using 'rhel7.0' instead. This alias will be removed in the future.
WARNING  /root/CentOS-7-x86_64-Minimal-2003.iso may not be accessible by the hypervisor. You will need to grant the 'qemu' user search permissions for the following directories: ['/root']
WARNING  /root/CentOS-7-x86_64-Minimal-2003.iso may not be accessible by the hypervisor. You will need to grant the 'qemu' user search permissions for the following directories: ['/root']

Starting install...
Retrieving file vmlinuz...                                                                                                                      | 6.4 MB  00:00:00     
Retrieving file initrd.img...                                                                                                                   |  53 MB  00:00:00     
Allocating 'centos7.qcow2'                                                                                                                      |  40 GB  00:00:05     
ERROR    Cannot get interface MTU on 'br0': No such device
Removing disk 'centos7.qcow2'                                                                                                                   |    0 B  00:00:00     
Domain installation does not appear to have been successful.
If it was, you can restart your domain by running:
  virsh --connect qemu:///system start centos7
otherwise, please restart your installation.

没有发现网桥 br0,使用ifconfig查看

[[email protected] ~]# ifconfig  |grep br0
virbr0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500

 名字应该是virbr0

继续修改

[[email protected] ~]# mkdir -p /home/kvm
[[email protected] ~]# mv Cent* /home/kvm
[[email protected] ~]#chown -R qemu:qemu /home/kvm
[[email protected] ~]#virt-install --name=centos7 --memory=1980,maxmemory=1980  --vcpus=2,maxvcpus=2 --os-type=linux --os-variant=rhel7 --location=/home/kvm/CentOS-7-x86_64-Minimal-2003.iso --disk path=/vms/centos7.qcow2,size=40 --connect qemu:///system  --bridge=br0 --graphics=none --console=pty,target_type=serial --extra-args="console=tty0 console=ttyS0"

安装开始

Starting installer, one moment...
anaconda 21.48.22.158-1 for CentOS 7 started.
 * installation log files are stored in /tmp during the installation
 * shell is available on TTY2
 * when reporting a bug add logs from /tmp as separate text/plain attachments
11:50:35 Not asking for VNC because we don't have a network
================================================================================
================================================================================
Installation

 1) [x] Language settings                 2) [!] Time settings
        (English (United States))                (Timezone is not set.)
 3) [!] Installation source               4) [!] Software selection
        (Processing...)                          (Processing...)
 5) [!] Installation Destination          6) [x] Kdump
        (No disks selected)                      (Kdump is enabled)
 7) [ ] Network configuration             8) [!] Root password
        (Not connected)                          (Password is not set.)
 9) [!] User creation
        (No user will be created)
  Please make your choice from above ['q' to quit | 'b' to begin installation |
  'r' to refresh]: 

[anaconda] 1:main* 2:shell  3:log  4:storage-lo> Switch tab: Alt+Tab | Help: F1 

 

结束安装