# 创建虚拟机

## 概述

在Ubuntu上创建KVM虚拟机有以下几种方式：

* [virt-manager](http://virt-manager.et.redhat.com/): GUI工具
* [virt-install](http://www.howtoforge.com/installing-kvm-guests-with-virt-install-on-ubuntu-8.10-server): Red Hat开发的python脚本，需要安装`virtinst`包
* ubuntu-vm-builder

> 推荐使用[virt-install](https://help.ubuntu.com/16.04/serverguide/libvirt.html#libvirt-virt-install)，主要原因是通用性 - 这个工具是RedHat开发，可以在RHEL和Ubuntu上使用，并且Ubuntu Server手册主要介绍这个工具。
>
> [ubuntu-vm-builder](http://manpages.ubuntu.com/manpages/xenial/man1/ubuntu-vm-builder.1.html)现在只是[vmbuilder](https://help.ubuntu.com/community/JeOSVMBuilder)（属于`pyton-vm-builder`包）的wrpper，主要维护用于兼容旧的脚本。

## 创建虚拟机

参考[在CentOS中部署KVM](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/in_action/deploy_kvm_on_centos/README.md)

### 安装Ubuntu 18.04 LTS (Bionic Beaver)

> 赞！终于找到正确的串口安装方法（`--console pty,target_type=serial --extra-args 'console=ttyS0,115200n8 serial'`）

```bash
virt-install \
--name ubuntu1804 \
--ram 2048 \
--disk path=/var/lib/libvirt/images/ubuntu1804.qcow2,size=10 \
--vcpus 1 \
--os-type linux \
--os-variant ubuntu16.04 \
--network bridge=virbr0 \
--graphics none \
--console pty,target_type=serial \
--location 'http://mirrors.163.com/ubuntu/dists/bionic/main/installer-amd64/' \
--extra-args 'console=ttyS0,115200n8 serial'
```

> 不过要注意，这个串口安装过程完成后，操作系统启动后依然不是默认从串口输出的，需要定制内核启动参数。虚拟机串口输出设置请参考[访问VM控制台](https://github.com/huataihuang/cloud-atlas-draft/tree/6f3204fffc11cf006abd394631e2598d98b415c3/virtual/kvm/startup/in_action/access_vm_console/README.md)
>
> 参考 [Easy headless KVM deployment with virt-install](https://blog.zencoffee.org/2016/06/easy-headless-kvm-deployment-virt-install/) 和 [Installing Virtual Machines with virt-install, plus copy pastable distro install one-liners](https://raymii.org/s/articles/virt-install_introduction_and_copy_paste_distro_install_commands.html) ，[virt-install(1) - Linux man page](https://linux.die.net/man/1/virt-install)
>
> 我尝试采用了`--console pty,target_type=virtio`表明采用virtio类型串口，`--extra-args 'console=tty0 console=ttyS0,115200'`，但是无法在控制台输入，提示

```
WARNING  Did not find 'console=hvc0' in --extra-args, which is likely required to see text install output from the guest.
```

然而，我修改成 `--extra-args 'console=hvc0 console=ttyS0,115200'`依然是相同提示信息，只不过终端输出了更多的启动硬件检测信息，但是没有登陆控制台。

所以还是按照[Easy headless KVM deployment with virt-install](https://blog.zencoffee.org/2016/06/easy-headless-kvm-deployment-virt-install/)设置。

### 终端安装模式

```bash
virt-install \
  --network bridge:virbr0 \
  --name centos7 \
  --ram=1024 \
  --vcpus=1 \
  --disk path=/var/lib/libvirt/images/centos7.img,size=10 \
  --graphics none \
  --location=http://mirrors.163.com/centos/7/os/x86_64/ \
  --extra-args="console=tty0 console=ttyS0,115200"
```

> 最初我使用的参数是`--extra-args="console=tty0 console=ttyS0,115200"` （模拟原先设置KVM虚拟机串口输出的参数）
>
> 报错`WARNING Did not find 'console=ttyS0' in --extra-args, which is likely required to see text install output from the guest.`
>
> 参考 [KVM Guest installed from console. But how to get to the guest's console?](https://serverfault.com/questions/257962/kvm-guest-installed-from-console-but-how-to-get-to-the-guests-console) 和 [KVM Install from Console](https://arstechnica.com/civis/viewtopic.php?f=16\&t=1165804) 应该改成 `--extra-args="console=tty0"`。
>
> 不过依然报错，但是只有终端输出没有终端输入。

上述采用了控制台方式安装

但是出现报错

```
[   76.466689] dracut-initqueue[585]: umount: /run/initramfs/squashfs: not mounted
[   76.470503] dracut-initqueue[585]: /sbin/dmsquash-live-root: line 273: printf: write error: No space left on device
[  241.174832] dracut-initqueue[584]: Warning: dracut-initqueue timeout - starting timeout scripts
...  不断打印这行超时日志
```

在打印超时日志后，进入终端修复模式

```
[  304.659694] dracut-initqueue[584]: Warning: Could not boot.
[  304.949309] dracut-initqueue[584]: Warning: /dev/root does not exist
         Starting Dracut Emergency Shell...
Warning: /dev/root does not exist

Generating "/run/initramfs/rdsosreport.txt"


Entering emergency mode. Exit the shell to continue.
Type "journalctl" to view system logs.
You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot
after mounting them and attach it to a bug report.


dracut:/#
```

* 删除重建虚拟机

```
virsh destroy centos7
virsh undefine centos7
```

尝试

```
virt-install \
--name centos7 \
--ram 1024 \
--vcpus 1 \
--disk path=/var/lib/libvirt/images/centos7.img,size=10 \
--os-type linux \
--os-variant rhl7.3 \
--network bridge=virbr0 \
--graphics none \
--console pty,target_type=serial \
--location 'http://mirrors.163.com/centos/7/os/x86_64/' \
--extra-args 'console=ttyS0,115200n8 serial'
```

> 如果使用`--os-variant centos7`会出现 `ERROR Error validating install location: Distro 'centos7' does not exist in our dictionary`报错，原来这个参数是根据`osinfo-query os`输出确定的。可以使用`rhl7.3`
>
> 参考 [Installing Virtual Machines with virt-install, plus copy pastable distro install one-liners](https://raymii.org/s/articles/virt-install_introduction_and_copy_paste_distro_install_commands.html)
>
> 可以尝试一下参考前面Ubuntu串口安装方法

改为采用VNC方式，通过图形界面处理：

```
virt-install \
  --network bridge:virbr0 \
  --name centos7 \
  --ram=2048 \
  --vcpus=1 \
  --os-type linux \
  --os-variant rhl7.3 \
  --disk path=/var/lib/libvirt/images/centos7.img,size=10 \
  --graphics vnc \
  --location=http://mirrors.163.com/centos/7/os/x86_64/
```

但是这次没有启动consle，只显示

```
WARNING  Graphics requested but DISPLAY is not set. Not running virt-viewer.
WARNING  No console to launch for the guest, defaulting to --wait -1
```

## 参考

* [KVM/CreateGuests](https://help.ubuntu.com/community/KVM/CreateGuests)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://huataihuang.gitbook.io/cloud-atlas-draft/virtual/kvm/kvm_on_ubuntu/create_guests.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.