1.21 Mapping Physical Storage to Virtual Disks

To specify a mapping between physical storage and the virtual disk, you might need to edit the virtual machine’s disk information. Follow the instructions in Section 1.3, Virtual Machine Settings, to change the device’s uname entry to the desired setting.

Example: Virtual Machine Output from Xend

(vbd
  (dev xvda:disk)
  (uname file:/var/lib/xen/images/oes2l/disk0)
  (mode w)
  (type disk)
  (backend 0)
        )

Table 1-6 uname Settings

Protocol

Description

Example

phy:

Block devices, such as a physical disk, in domain 0

phy:/dev/hda

file:

Raw disk images accessed by using loopback

file:/path/file

tap:aio:

Raw disk images accessed by using blktap. Similar to loopback but with better performance

tap:aio:/path/file

tap:vmdk:

VMware disk images accessed by using blktap

tap:vmdk:/path/file

nbd:

Raw disk images accessed by using NBD

ndb: ip_port

tap:qcow:

QEMU disk images accessed by using blktap

tap:qcow/path/file

iscsi:

iSCSI targets using connections initiated from domain 0

iscsi:IQN,LUN

npiv:

Fibre Channel connections initiated from domain 0

npiv:NPIV,LUN