Red Hat SummitCe contenu n'est pas disponible dans la langue sélectionnée.
7.4. I/O Mode
I/O mode options can be configured on a virtual machine during installation with virt-manager or the
virt-install command, or on an existing guest by editing the guest XML configuration.
| Caching Option | Description |
|---|---|
| IO=native | The default for Red Hat Enterprise Virtualization environments. This mode uses kernel asynchronous I/O with direct I/O options. |
| IO=threads | Sets the I/O mode to host user-mode based threads. |
| IO=default | Sets the I/O mode to the kernel default. In Red Hat Enterprise Linux 6, the default is IO=threads. |
In virt-manager, the I/O mode can be specified under Virtual Disk. For information on using virt-manager to change the I/O mode, see Section 3.4, “Virtual Disk Performance Options”
To configure the I/O mode in the guest XML, use
Copy to Clipboard
Copied!
Toggle word wrap
Toggle overflow
virsh edit to edit the io setting inside the driver tag, specifying native, threads, or default. For example, to set the I/O mode to threads:
<disk type='file' device='disk'>
<driver name='qemu' type='raw' io='threads'/>
<disk type='file' device='disk'>
<driver name='qemu' type='raw' io='threads'/>
To configure the I/O mode when installing a guest using
virt-install, add the io option to the --disk path parameter. For example, to configure io=threads during guest installation:
virt-install \ --disk path=/storage/images/$NAME.img,io=threads,opt2=val2... ....
virt-install \
--disk path=/storage/images/$NAME.img,io=threads,opt2=val2...
....
'%20d='M201.5%20305.5c-13.8%200-24.9-11.1-24.9-24.6%200-13.8%2011.1-24.9%2024.9-24.9%2013.6%200%2024.6%2011.1%2024.6%2024.9%200%2013.6-11.1%2024.6-24.6%2024.6zM504%20256c0%20137-111%20248-248%20248S8%20393%208%20256%20119%208%20256%208s248%20111%20248%20248zm-132.3-41.2c-9.4%200-17.7%203.9-23.8%2010-22.4-15.5-52.6-25.5-86.1-26.6l17.4-78.3%2055.4%2012.5c0%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.3%2024.9-24.9s-11.1-24.9-24.9-24.9c-9.7%200-18%205.8-22.1%2013.8l-61.2-13.6c-3-.8-6.1%201.4-6.9%204.4l-19.1%2086.4c-33.2%201.4-63.1%2011.3-85.5%2026.8-6.1-6.4-14.7-10.2-24.1-10.2-34.9%200-46.3%2046.9-14.4%2062.8-1.1%205-1.7%2010.2-1.7%2015.5%200%2052.6%2059.2%2095.2%20132%2095.2%2073.1%200%20132.3-42.6%20132.3-95.2%200-5.3-.6-10.8-1.9-15.8%2031.3-16%2019.8-62.5-14.9-62.5zM302.8%20331c-18.2%2018.2-76.1%2017.9-93.6%200-2.2-2.2-6.1-2.2-8.3%200-2.5%202.5-2.5%206.4%200%208.6%2022.8%2022.8%2087.3%2022.8%20110.2%200%202.5-2.2%202.5-6.1%200-8.6-2.2-2.2-6.1-2.2-8.3%200zm7.7-75c-13.6%200-24.6%2011.1-24.6%2024.9%200%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.1%2024.9-24.6%200-13.8-11-24.9-24.9-24.9z'/%3e%3c/svg%3e){kind=small}