在主机系统(Debian Jessie)中,对于win7 guest虚拟机的qemu进程,顶部始终显示30-70%(或更多)的cpu负载,即使guest虚拟机中的taskmanager处于零cpu负载.
top - 11:12:08 up 6 days,1:47,1 user,load average: 0,70,62,55 Tasks: 216 total,2 running,214 sleeping,0 stopped,0 zombie %cpu(s): 5,0 us,3,7 sy,0 ni,91,3 id,0 wa,0 hi,0 si,0 st KiB Mem: 24776900 total,21591188 used,3185712 free,122680 buffers KiB Swap: 3905532 total,60748 used,3844784 free. 399364 cached Mem PID USER PR NI VIRT RES SHR S %cpu %MEM TIME+ COMMAND 11138 libvirt+ 20 0 10,804g 8,243g 18536 R 70,1 34,9 2137:30 qemu-system-x86 12134 libvirt+ 20 0 7309216 6,046g 18792 S 3,7 25,6 139:13.88 qemu-system-x86 12055 libvirt+ 20 0 8900940 4,057g 18500 S 2,3 17,2 109:41.87 qemu-system-x86 12041 libvirt+ 20 0 2956240 1,388g 18292 S 2,0 5,9 61:38.55 qemu-system-x86 5569 root 20 0 1007924 23456 11012 S 1,0 0,1 1:16.86 libvirtd
在guest虚拟机内部运行MSsql 2008 R2 Express.为此设置Traceflag -T8038(根据proxmox performance tweaks).此外,平板电脑设备已从配置中删除,并且客户端内的虚拟设备已禁用(因为我不知道如何在VM配置中禁用它).
此外,它还运行Pervasive sql 8服务器来触发旧的btrieve数据库.
奇怪的是,如果我从guest虚拟机中完全删除所有NIC,则顶部的cpu负载会降至足够的水平(1-3%).实际上,作为一个NIC我通过其中一个物理网卡(Intel I350).但是虚拟化NIC的行为是相同的.
所有测试都没有连接任何客户端.
实际访客配置:
<domain type='kvm'> <name>win7</name> <uuid>4b62c825-07ce-49b9-be8c-63f1f51ec28c</uuid> <memory unit='KiB'>8388608</memory> <currentMemory unit='KiB'>8388608</currentMemory> <vcpu placement='static'>2</vcpu> <os> <type arch='x86_64' machine='pc-i440fx-2.1'>hvm</type> </os> <features> <acpi/> <apic/> <hyperv> <relaxed state='on'/> <vapic state='on'/> <spinlocks state='on' retries='8191'/> </hyperv> </features> <cpu mode='host-model'> <model fallback='allow'/> <topology sockets='1' cores='2' threads='1'/> </cpu> <clock offset='localtime'> <timer name='rtc' tickpolicy='catchup'/> <timer name='pit' tickpolicy='delay'/> <timer name='hpet' present='no'/> <timer name='hypervclock' present='yes'/> </clock> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <pm> <suspend-to-mem enabled='no'/> <suspend-to-disk enabled='no'/> </pm> <devices> <emulator>/usr/bin/kvm</emulator> <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <source dev='/dev/vg_vm/lv_win7Pro'/> <target dev='vda' bus='virtio'/> <boot order='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </disk> <disk type='file' device='cdrom'> <driver name='qemu' type='raw'/> <target dev='hdb' bus='ide'/> <readonly/> <address type='drive' controller='0' bus='0' target='0' unit='1'/> </disk> <controller type='usb' index='0' model='ich9-ehci1'> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x7'/> </controller> <controller type='usb' index='0' model='ich9-uhci1'> <master startport='0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0' multifunction='on'/> </controller> <controller type='usb' index='0' model='ich9-uhci2'> <master startport='2'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x1'/> </controller> <controller type='usb' index='0' model='ich9-uhci3'> <master startport='4'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x2'/> </controller> <controller type='pci' index='0' model='pci-root'/> <controller type='ide' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/> </controller> <controller type='virtio-serial' index='0'> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </controller> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <channel type='spicevmc'> <target type='virtio' name='com.redhat.spice.0'/> <address type='virtio-serial' controller='0' bus='0' port='1'/> </channel> <input type='mouse' bus='ps2'/> <input type='keyboard' bus='ps2'/> <graphics type='vnc' port='-1' autoport='yes'/> <video> <model type='qxl' ram='65536' vram='65536' heads='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <hostdev mode='subsystem' type='pci' managed='yes'> <source> <address domain='0x0000' bus='0x07' slot='0x00' function='0x1'/> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/> </hostdev> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> </domain>
什么可能导致这个以及如何改进?
解决方法
要进行调试,请执行以下步骤:
>停止你的MSsql实例.主机负载是否减少?如果是这样,你找到了罪魁祸首.关键是MSsql使用高定时器频率(1ms),即使在空闲时也是如此.在裸机上这不是一个问题(系统将只使用更多的瓦特),但在虚拟化的一个可能是一个问题.如果可能,您应该确定Windows正在使用的计时器源,并尝试在可用的源之间切换.作为一种变通方法,存在一个补丁,用于将时钟定时器中断提高到12ms.有关更多信息,请参阅here和here.
>如果点n.1没有带来任何好处,那么问题可能与HAL有关.我看到你正在使用两个vcpu;尝试使用单个vcpu启动VM.这有什么改变吗?如果不是,请执行Windows硬件选项卡的屏幕截图(展开HAL节点)并在此处报告.
编辑:好的,似乎MSsql和HAL也不是导致主机负载的根本原因.继续第二个调试阶段:
>停止虚拟机并从其定义中删除所有USB设备.重启机器并检查主机负载:它改变了吗?>如果不是,请使用powertop实用程序监控主机的cpu活动.在这里,您应该看到最常用的软件例程/中断.在30秒内运行并在此处报告.