43-KVM虚拟化-利用libvirt服务进行KVM虚拟机管理

Posted 2023-01-02

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半虚拟化驱动virtio的工作原理

为了提高内存、硬盘、网络的性能，需要支持半虚拟化

43-KVM虚拟化-利用libvirt服务进行KVM虚拟机管理_libvirtd

virtio 是一种 I/O 半虚拟化解决方案，是一套通用 I/O 设备虚拟化的程序，是对半虚拟化 Hypervisor 中的一组通用 I/O 设备的抽象，提供了一套上层应用与各 Hypervisor 虚拟化设备（KVM，Xen，VMware等）之间的通信框架和编程接口，减少跨平台所带来的兼容性问题，大大提高驱动程序开发效率，Windows 系统需要单独安装virtio驱动，Linux系统自带virtio驱动。

libvirt 架构

43-KVM虚拟化-利用libvirt服务进行KVM虚拟机管理_虚拟化_02

如果libvirtd服务意外关闭,将导致相关工具,如:virt-manager等无法和虚拟机连接,但虚拟机仍会正常运行

[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
------------------------------------
 2    centos7-mooreyxia   running
 -    rocky8              shut off

[root@ubuntu2204 ~]#systemctl status libvirtd
● libvirtd.service - Virtualization daemon
     Loaded: loaded (/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
     Active: active (running) since Sat 2022-12-31 17:53:28 CST; 17h ago
TriggeredBy: ● libvirtd-ro.socket
             ● libvirtd.socket
             ● libvirtd-admin.socket
       Docs: man:libvirtd(8)
             https://libvirt.org
   Main PID: 871 (libvirtd)
      Tasks: 23 (limit: 32768)
     Memory: 72.6M
        CPU: 9.258s
     CGroup: /system.slice/libvirtd.service
             ├─871 /usr/sbin/libvirtd
             ├─987 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper
             └─988 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper

Dec 31 17:53:30 ubuntu2204.wang.org dnsmasq[987]: using nameserver 127.0.0.53#53
Dec 31 17:53:30 ubuntu2204.wang.org dnsmasq[987]: read /etc/hosts - 7 addresses
Dec 31 17:53:30 ubuntu2204.wang.org dnsmasq[987]: read /var/lib/libvirt/dnsmasq/default.addnhosts - 0 addresses
Dec 31 17:53:30 ubuntu2204.wang.org dnsmasq-dhcp[987]: read /var/lib/libvirt/dnsmasq/default.hostsfile
Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPDISCOVER(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPOFFER(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPREQUEST(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPACK(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:18:35 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPREQUEST(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:18:35 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPACK(virbr0) 192.168.122.23 52:54:00:18:b7:d2

#停止libvirtd服务，socket还在运行，systemctl会自动激活socket，所以libvirtd会自动重启
[root@ubuntu2204 ~]#systemctl stop libvirtd
Warning: Stopping libvirtd.service, but it can still be activated by:
  libvirtd-ro.socket
  libvirtd.socket
  libvirtd-admin.socket
[root@ubuntu2204 ~]#systemctl status libvirtd-ro.socket
● libvirtd-ro.socket - Libvirt local read-only socket
     Loaded: loaded (/lib/systemd/system/libvirtd-ro.socket; enabled; vendor preset: enabled)
     Active: active (listening) since Sat 2022-12-31 17:53:24 CST; 17h ago
   Triggers: ● libvirtd.service
     Listen: /run/libvirt/libvirt-sock-ro (Stream)
     CGroup: /system.slice/libvirtd-ro.socket

Dec 31 17:53:24 ubuntu2204.wang.org systemd[1]: Listening on Libvirt local read-only socket.
[root@ubuntu2204 ~]#systemctl status libvirtd
○ libvirtd.service - Virtualization daemon
     Loaded: loaded (/lib/systemd/system/libvirtd.service; enabled; vendor preset: enabled)
     Active: inactive (dead) since Sun 2023-01-01 11:27:32 CST; 1min 32s ago
TriggeredBy: ● libvirtd-ro.socket
             ● libvirtd.socket
             ● libvirtd-admin.socket
       Docs: man:libvirtd(8)
             https://libvirt.org
    Process: 871 ExecStart=/usr/sbin/libvirtd $LIBVIRTD_ARGS (code=exited, status=0/SUCCESS)
   Main PID: 871 (code=exited, status=0/SUCCESS)
      Tasks: 2 (limit: 32768)
     Memory: 57.1M
        CPU: 9.370s
     CGroup: /system.slice/libvirtd.service
             ├─987 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper
             └─988 /usr/sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf --leasefile-ro --dhcp-script=/usr/lib/libvirt/libvirt_leaseshelper

Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPREQUEST(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:11:55 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPACK(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:18:35 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPREQUEST(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:18:35 ubuntu2204.wang.org dnsmasq-dhcp[987]: DHCPACK(virbr0) 192.168.122.23 52:54:00:18:b7:d2
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: Stopping Virtualization daemon...
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: libvirtd.service: Deactivated successfully.
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: libvirtd.service: Unit process 987 (dnsmasq) remains running after unit stopped.
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: libvirtd.service: Unit process 988 (dnsmasq) remains running after unit stopped.
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: Stopped Virtualization daemon.
Jan 01 11:27:32 ubuntu2204.wang.org systemd[1]: libvirtd.service: Consumed 9.370s CPU time.

#彻底停掉libvirt服务，发现虚拟机还在运行，只是连接虚拟机的窗口失效
[root@ubuntu2204 ~]#systemctl stop libvirtd libvirtd.socket libvirtdadmin.socket libvirtd-ro.socket
Failed to stop libvirtdadmin.socket: Unit libvirtdadmin.socket not loaded.
[root@ubuntu2204 ~]#virsh list --all
error: failed to connect to the hypervisor
error: Failed to connect socket to /var/run/libvirt/libvirt-sock: Connection refused
[root@ubuntu2204 ~]#ps aux |grep kvm
root        1247  0.0  0.0      0     0 ?        I    10:52   0:02 [kworker/5:0-kvm-irqfd-cleanup]
libvirt+    1575  5.8  3.2 3853876 532360 ?      Sl   11:17   0:55 /usr/bin/qemu-system-x86_64 -name guest=centos7-mooreyxia,debug-threads=on -S -object "qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain-2-centos7-mooreyxia/master-key.aes" -machine pc-q35-6.2,usb=off,vmport=off,dump-guest-core=off,memory-backend=pc.ram -accel kvm -cpu host,migratable=on -m 2048 -object "qom-type":"memory-backend-ram","id":"pc.ram","size":2147483648 -overcommit mem-lock=off -smp 2,sockets=2,cores=1,threads=1 -uuid 3492dccc-468d-4fe9-8ec8-b4a251dccf00 -no-user-config -nodefaults -chardev socket,id=charmonitor,fd=33,server=on,wait=off -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device pcie-root-port,port=16,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2 -device pcie-root-port,port=17,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 -device pcie-root-port,port=18,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 -device pcie-root-port,port=19,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3 -device pcie-root-port,port=20,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 -device pcie-root-port,port=21,chassis=6,id=pci.6,bus=pcie.0,addr=0x2.0x5 -device pcie-root-port,port=22,chassis=7,id=pci.7,bus=pcie.0,addr=0x2.0x6 -device pcie-root-port,port=23,chassis=8,id=pci.8,bus=pcie.0,addr=0x2.0x7 -device pcie-root-port,port=24,chassis=9,id=pci.9,bus=pcie.0,multifunction=on,addr=0x3 -device pcie-root-port,port=25,chassis=10,id=pci.10,bus=pcie.0,addr=0x3.0x1 -device pcie-root-port,port=26,chassis=11,id=pci.11,bus=pcie.0,addr=0x3.0x2 -device pcie-root-port,port=27,chassis=12,id=pci.12,bus=pcie.0,addr=0x3.0x3 -device pcie-root-port,port=28,chassis=13,id=pci.13,bus=pcie.0,addr=0x3.0x4 -device pcie-root-port,port=29,chassis=14,id=pci.14,bus=pcie.0,addr=0x3.0x5 -device qemu-xhci,p2=15,p3=15,id=usb,bus=pci.2,addr=0x0 -device virtio-serial-pci,id=virtio-serial0,bus=pci.3,addr=0x0 -blockdev "driver":"file","filename":"/var/lib/libvirt/images/centos7-mooreyxia.qcow2","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap" -blockdev "node-name":"libvirt-2-format","read-only":false,"discard":"unmap","driver":"qcow2","file":"libvirt-2-storage","backing":null -device virtio-blk-pci,bus=pci.4,addr=0x0,drive=libvirt-2-format,id=virtio-disk0,bootindex=1 -device ide-cd,bus=ide.0,id=sata0-0-0 -netdev tap,fd=34,id=hostnet0,vhost=on,vhostfd=36 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:18:b7:d2,bus=pci.1,addr=0x0 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev socket,id=charchannel0,fd=32,server=on,wait=off -device virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0 -chardev spicevmc,id=charchannel1,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=2,chardev=charchannel1,id=channel1,name=com.redhat.spice.0 -device usb-tablet,id=input0,bus=usb.0,port=1 -audiodev "id":"audio1","driver":"spice" -spice port=5900,addr=127.0.0.1,disable-ticketing=on,image-compression=off,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pcie.0,addr=0x1 -device ich9-intel-hda,id=sound0,bus=pcie.0,addr=0x1b -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0,audiodev=audio1 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=2 -chardev spicevmc,id=charredir1,name=usbredir -device usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=3 -device virtio-balloon-pci,id=balloon0,bus=pci.5,addr=0x0 -object "qom-type":"rng-random","id":"objrng0","filename":"/dev/urandom" -device virtio-rng-pci,rng=objrng0,id=rng0,bus=pci.6,addr=0x0 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny -msg timestamp=on
root        1581  0.0  0.0      0     0 ?        S    11:17   0:00 [kvm-nx-lpage-re]
root        1586  0.0  0.0      0     0 ?        S    11:17   0:00 [kvm-pit/1575]
root        1781  0.0  0.0   9696  2404 pts/1    S+   11:33   0:00 grep --color=auto kvm

#重启libvirtd服务，就可以继续连接kvm进行管理
[root@ubuntu2204 ~]#systemctl start libvirtd 
[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
------------------------------------
 2    centos7-mooreyxia   running
 -    rocky8              shut off

virt-manager 管理虚拟机

virt-manager是一个图形化工具,主要功能:

定义和创建虚拟机
硬件管理
性能监视
控制台
在线和离线迁移
虚拟机的保存和恢复、暂停和继续、关闭和启动

43-KVM虚拟化-利用libvirt服务进行KVM虚拟机管理_libvirtd_03

virsh 命令行工具

virsh是使用libvirt managementAPI构建的管理工具,相比virt-manager可以提高效率

#virsh 主要功能
[root@ubuntu2204 ~]#virsh --help
virsh [options]... [<command_string>]
virsh [options]... <command> [args...]
options:
-c | --connect=URI hypervisor connection URI
-d | --debug=NUM debug level [0-4]
-e | --escape <char> set escape sequence for console
-h | --help this help
-k | --keepalive-interval=NUM
keepalive interval in seconds, 0 for disable
-K | --keepalive-count=NUM
number of possible missed keepalive messages
-l | --log=FILE output logging to file
-q | --quiet quiet mode
-r | --readonly connect readonly
-t | --timing print timing information
-v short version
-V long version
--version[=TYPE] version, TYPE is short or long (default short)
....
Domain Management (help keyword domain):
Domain Monitoring (help keyword monitor):
Host and Hypervisor (help keyword host):
Interface (help keyword interface):
Network Filter (help keyword filter):
Networking (help keyword network):
Node Device (help keyword nodedev):
Secret (help keyword secret):
Snapshot (help keyword snapshot):
Storage Pool (help keyword pool):
Storage Volume (help keyword volume):
Virsh itself (help keyword virsh):

#virsh 子命令说明
help #打印基本帮助信息
attach-device #使用XML文件中的设备定义在虚拟机中添加设备
attach-disk #在虚拟机中附加新磁盘设备
attach-interface #在虚拟机中附加新网络接口
create #从 XML 配置文件生成虚拟机并启动新虚拟机
define #为虚拟机输出XML配置文件
destroy #强制虚拟机停止
detach-device #从虚拟机中分离设备，使用同样的XML 描述作为命令
attach-device
detach-disk #从虚拟机中分离磁盘设备
detach-interface #从虚拟机中分离网络接口
domblkstat #显示正在运行的虚拟机的块设备统计
domid #显示虚拟机ID
domifstat #显示正在运行的虚拟机的网络接口统计
dominfo #显示虚拟机信息
domname #显示虚拟机名称
domstate #显示虚以机状态
domuuid #显示虚拟机UUID
dumpxml #输出虚拟机 XML配置文件
list #列出所有虚拟机
migrate #将虚拟机迁移到另一台主机中
nodeinfo #有关管理程序的输出信息
quit #退出这个互动终端
reboot #重新启动虚拟机
restore #恢复以前保存在文件中的虚拟机
resume #恢复暂停的虚拟机
save #将虚拟机当前状态保存到某个文件中
setmaxmem #为管理程序设定内存上限
setmem #为虚拟机设定分配的内存
setvcpus #修改为虚拟机分配的虚拟CPU数目
shutdown #关闭某个虚拟机
start #启动未激活的虚拟机
suspend #暂停虚拟机
undefine #删除与虚拟机关联的所有文件
vepuinfo #显示虚以机的虚拟CPU信息
vcpupin #控制虚拟机的虚拟CPU亲和性
version #显示virsh版本

#查看子命令 list 命令用法
[root@ubuntu2204 ~]#virsh help list
  NAME
    list - list domains

  SYNOPSIS
    list [--inactive] [--all] [--transient] [--persistent] [--with-snapshot] [--without-snapshot] [--with-checkpoint] [--without-checkpoint] [--state-running] [--state-paused] [--state-shutoff] [--state-other] [--autostart] [--no-autostart] [--with-managed-save] [--without-managed-save] [--uuid] [--name] [--id] [--table] [--managed-save] [--title]

  DESCRIPTION
    Returns list of domains.

  OPTIONS
    --inactive       list inactive domains
    --all            list inactive & active domains
    --transient      list transient domains
    --persistent     list persistent domains
    --with-snapshot  list domains with existing snapshot
    --without-snapshot  list domains without a snapshot
    --with-checkpoint  list domains with existing checkpoint
    --without-checkpoint  list domains without a checkpoint
    --state-running  list domains in running state
    --state-paused   list domains in paused state
    --state-shutoff  list domains in shutoff state
    --state-other    list domains in other states
    --autostart      list domains with autostart enabled
    --no-autostart   list domains with autostart disabled
    --with-managed-save  list domains with managed save state
    --without-managed-save  list domains without managed save
    --uuid           list uuids only
    --name           list domain names only
    --id             list domain IDs only
    --table          list table (default)
    --managed-save   mark inactive domains with managed save state
    --title          show domain title

例：
[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
------------------------------------
 2    centos7-mooreyxia   running
 -    rocky8              shut off
[root@ubuntu2204 ~]#virsh start rocky8
Domain rocky8 started

[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
-----------------------------------
 2    centos7-mooreyxia   running
 3    rocky8              running

[root@ubuntu2204 ~]#virsh shutdown 3
Domain 3 is being shutdown
#列出开机状态虚拟机的UUID和名称
[root@ubuntu2204 ~]#virsh list --uuid --name
3492dccc-468d-4fe9-8ec8-b4a251dccf00 centos7-mooreyxia
3a984e57-70f4-428d-8f30-3127dd4e9be2 rocky8

案例：查看虚拟机UUID,通过UUID启动关闭虚拟机

[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
-----------------------------------
 2    centos7-mooreyxia   running
 3    rocky8              running
[root@ubuntu2204 ~]#virsh domuuid 3
3a984e57-70f4-428d-8f30-3127dd4e9be2
[root@ubuntu2204 ~]#virsh destroy 3a984e57-70f4-428d-8f30-3127dd4e9be2
Domain 3a984e57-70f4-428d-8f30-3127dd4e9be2 destroyed

[root@ubuntu2204 ~]#virsh list --all
 Id   Name                State
------------------------------------
 2    centos7-mooreyxia   running
 -    rocky8              shut off

案例：暂停和恢复虚拟机

[root@ubuntu2204 ~]#virsh list
 Id   Name                State
-----------------------------------
 2    centos7-mooreyxia   running

[root@ubuntu2204 ~]#virsh suspend centos7-mooreyxia
Domain centos7-mooreyxia suspended

[root@ubuntu2204 ~]#virsh list
 Id   Name                State
----------------------------------
 2    centos7-mooreyxia   paused

[root@ubuntu2204 ~]#ps aux|grep kvm
root        1247  0.0  0.0      0     0 ?        I    10:52   0:02 [kworker/5:0-kvm-irqfd-cleanup]
libvirt+    1575  2.3  3.3 3862072 550556 ?      Sl   11:17   1:13 /usr/bin/qemu-system-x86_64 -name guest=centos7-mooreyxia,debug-threads=on -S -object "qom-type":"secret","id":"masterKey0","format":"raw","file":"/var/lib/libvirt/qemu/domain-2-centos7-mooreyxia/master-key.aes" -machine pc-q35-6.2,usb=off,vmport=off,dump-guest-core=off,memory-backend=pc.ram -accel kvm -cpu host,migratable=on -m 2048 -object "qom-type":"memory-backend-ram","id":"pc.ram","size":2147483648 -overcommit mem-lock=off -smp 2,sockets=2,cores=1,threads=1 -uuid 3492dccc-468d-4fe9-8ec8-b4a251dccf00 -no-user-config -nodefaults -chardev socket,id=charmonitor,fd=33,server=on,wait=off -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device pcie-root-port,port=16,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2 -device pcie-root-port,port=17,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 -device pcie-root-port,port=18,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 -device pcie-root-port,port=19,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3 -device pcie-root-port,port=20,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 -device pcie-root-port,port以上是关于43-KVM虚拟化-利用libvirt服务进行KVM虚拟机管理的主要内容，如果未能解决你的问题，请参考以下文章 
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