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
On a Friday in 2023, Peter Krempa wrote: >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(+) > Reviewed-by: Ján Tomko <jtomko@redhat.com> Jano
On Fri, Aug 25, 2023 at 02:34:04PM +0200, Peter Krempa wrote: > 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(+) Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
© 2016 - 2024 Red Hat, Inc.