KVM——磁碟性能

我有虛擬機並將物理磁碟附加到它：

<pool type='disk'>
 <name>X</name>
 <uuid>0119698d-d28a-fbc8-6ca3-40c485957e49</uuid>
 <capacity>2000396321280</capacity>
 <allocation>2000388063744</allocation>
 <available>8225280</available>
 <source>
   <device path='/dev/sdb'>
   <freeExtent start='2000388096000' end='2000396321280'/>
   </device>
   <format type='dos'/>
 </source>
 <target>
   <path>/dev</path>
   <permissions>
     <mode>0700</mode>
     <owner>-1</owner>
     <group>-1</group>
   </permissions>
 </target>
</pool>

我的虛擬機有 1 個核心和 2GB 記憶體。當我複製文件時，我的傳輸速率為 7MB/s。

<domain type='kvm' id='7'>
 <name>gfs-6</name>
 <uuid>4061a8b3-860b-3aaa-5014-36c3dbc15ca4</uuid>
 <memory>2097152</memory>
 <currentMemory>2097152</currentMemory>
 <vcpu>1</vcpu>
 <os>
   <type arch='x86_64' machine='pc-0.14'>hvm</type>
   <boot dev='hd'/>
   <bootmenu enable='no'/>
 </os>
 <features>
   <acpi/>
   <pae/>
 </features>
 <clock offset='utc'/>
 <on_poweroff>destroy</on_poweroff>
 <on_reboot>restart</on_reboot>
 <on_crash>restart</on_crash>
 <devices>
   <emulator>/usr/bin/kvm</emulator>
   <disk type='file' device='disk'>
     <driver name='qemu' type='raw'/>
     <source file='/opt/vm/gfs-6.img'/>
     <target dev='vda' bus='virtio'/>
     <alias name='virtio-disk0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
   </disk>
   <disk type='block' device='disk'>
     <driver name='qemu' type='raw'/>
     <source dev='/dev/sdb1'/>
     <target dev='sda' bus='scsi'/>
     <alias name='scsi0-0-0'/>
     <address type='drive' controller='0' bus='0' unit='0'/>
   </disk>
   <controller type='ide' index='0'>
     <alias name='ide0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x1'/>
   </controller>
   <controller type='scsi' index='0'>
     <alias name='scsi0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
   </controller>
   <interface type='bridge'>
     <mac address='52:54:00:2a:56:5e'/>
     <source bridge='br1'/>
     <target dev='vnet1'/>
     <model type='e1000'/>
     <alias name='net0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
   </interface>
   <serial type='pty'>
     <source path='/dev/pts/2'/>
     <target port='0'/>
     <alias name='serial0'/>
   </serial>
   <console type='pty' tty='/dev/pts/2'>
     <source path='/dev/pts/2'/>
     <target type='serial' port='0'/>
     <alias name='serial0'/>
   </console>
   <input type='mouse' bus='ps2'/>
   <graphics type='vnc' port='5901' autoport='yes'/>
   <video>
     <model type='cirrus' vram='9216' heads='1'/>
     <alias name='video0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/>
   </video>
   <memballoon model='virtio'>
     <alias name='balloon0'/>
     <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
   </memballoon>
 </devices>
 <seclabel type='dynamic' model='apparmor'>
   <label>libvirt-4061a8b3-860b-3aaa-5014-36c3dbc15ca4</label>
   <imagelabel>libvirt-4061a8b3-860b-3aaa-5014-36c3dbc15ca4</imagelabel>
 </seclabel>
</domain>

我做錯了什麼？我想在我的虛擬機上獲得更好的磁碟性能。

您應該使用virtio而不是 scsi，它更快。

  <target dev='sda' bus='scsi'/>

您可以在儲存部分找到一些參考資料

通過直接訪問磁碟，您幾乎肯定會獲得性能提升。這有時被稱為“半虛擬化”，當使用 KVM 時需要使用 virtio 驅動程序（請注意，這也可以用於網路設備）。

詳細資訊可以在這裡找到：http ://wiki.libvirt.org/page/Virtio

引用自：https://serverfault.com/questions/353008