7.3. I/O Mode

I/O mode options can be configured with virt-manager during guest installation, or on an existing guest virtual machine by editing the guest XML configuration.

Table 7.2. IO mode options

IO Mode OptionDescription
IO=nativeThe default for Red Hat Virtualization (RHV) environments. This mode refers to kernel asynchronous I/O with direct I/O options.
IO=threadsThe default are host user-mode based threads.
IO=defaultThe default in Red Hat Enterprise Linux 7 is threads mode.
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 3.3, “Virtual Disk Performance Options”
To configure the I/O mode in the guest XML, 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'/>