Note the implications and caveats of <disk type='dir'>. Closes: https://gitlab.com/libvirt/libvirt/-/issues/519 Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- docs/formatdomain.rst | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index cd9cb02bf8..9787933d4d 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -2634,6 +2634,12 @@ paravirtualized driver is specified via the ``disk`` element. </source> <target dev='sdb' bus='scsi'/> </disk> + <disk type='dir' device='floppy'> + <driver name='qemu' type='fat'/> + <source dir='/var/somefiles'> + <target dev='fda'/> + <readonly/> + </disk> <disk type='volume' device='disk'> <driver name='qemu' type='raw'/> <source pool='iscsi-pool' volume='unit:0:0:1' mode='host'/> @@ -2757,6 +2763,18 @@ paravirtualized driver is specified via the ``disk`` element. ``dir`` The ``dir`` attribute specifies the fully-qualified path to the directory to use as the disk. :since:`Since 0.7.5` + + Note that most hypervisors that support ``dir`` disks do that by exposing + an emulated block device with an emulated filesystem populated with + contents of the configured directory. As guest operating system may cache + the filesystem metadata, outside changes to the directory may not appear + in the guest and/or may result in corrupted data being observable from + the VM. + + The format of the emulated filesystem is controlled by the ``format`` + attribute of the ``<driver>`` driver element. Currently only the ``fat`` + format is supported. Hypervisors may only support ``<readonly/>`` mode. + ``network`` The ``protocol`` attribute specifies the protocol to access to the requested image. Possible values are "nbd", "iscsi", "rbd", "sheepdog", -- 2.41.0