[mirror_qemu.git] / docs / system / device-url-syntax.rst.inc


In addition to using normal file images for the emulated storage
devices, QEMU can also use networked resources such as iSCSI devices.
These are specified using a special URL syntax.

``iSCSI``
   iSCSI support allows QEMU to access iSCSI resources directly and use
   as images for the guest storage. Both disk and cdrom images are
   supported.

   Syntax for specifying iSCSI LUNs is
   "iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>"

   By default qemu will use the iSCSI initiator-name
   'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from
   the command line or a configuration file.

   Since version Qemu 2.4 it is possible to specify a iSCSI request
   timeout to detect stalled requests and force a reestablishment of the
   session. The timeout is specified in seconds. The default is 0 which
   means no timeout. Libiscsi 1.15.0 or greater is required for this
   feature.

   Example (without authentication):

   .. parsed-literal::

      |qemu_system| -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
                       -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
                       -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

   Example (CHAP username/password via URL):

   .. parsed-literal::

      |qemu_system| -drive file=iscsi://user%password@192.0.2.1/iqn.2001-04.com.example/1

   Example (CHAP username/password via environment variables):

   .. parsed-literal::

      LIBISCSI_CHAP_USERNAME="user" \
      LIBISCSI_CHAP_PASSWORD="password" \
      |qemu_system| -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

``NBD``
   QEMU supports NBD (Network Block Devices) both using TCP protocol as
   well as Unix Domain Sockets. With TCP, the default port is 10809.

   Syntax for specifying a NBD device using TCP, in preferred URI form:
   "nbd://<server-ip>[:<port>]/[<export>]"

   Syntax for specifying a NBD device using Unix Domain Sockets;
   remember that '?' is a shell glob character and may need quoting:
   "nbd+unix:///[<export>]?socket=<domain-socket>"

   Older syntax that is also recognized:
   "nbd:<server-ip>:<port>[:exportname=<export>]"

   Syntax for specifying a NBD device using Unix Domain Sockets
   "nbd:unix:<domain-socket>[:exportname=<export>]"

   Example for TCP

   .. parsed-literal::

      |qemu_system| --drive file=nbd:192.0.2.1:30000

   Example for Unix Domain Sockets

   .. parsed-literal::

      |qemu_system| --drive file=nbd:unix:/tmp/nbd-socket

``SSH``
   QEMU supports SSH (Secure Shell) access to remote disks.

   Examples:

   .. parsed-literal::

      |qemu_system| -drive file=ssh://user@host/path/to/disk.img
      |qemu_system| -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img

   Currently authentication must be done using ssh-agent. Other
   authentication methods may be supported in future.

``Sheepdog``
   Sheepdog is a distributed storage system for QEMU. QEMU supports
   using either local sheepdog devices or remote networked devices.

   Syntax for specifying a sheepdog device

   ::

      sheepdog[+tcp|+unix]://[host:port]/vdiname[?socket=path][#snapid|#tag]

   Example

   .. parsed-literal::

      |qemu_system| --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine

   See also https://sheepdog.github.io/sheepdog/.

``GlusterFS``
   GlusterFS is a user space distributed file system. QEMU supports the
   use of GlusterFS volumes for hosting VM disk images using TCP, Unix
   Domain Sockets and RDMA transport protocols.

   Syntax for specifying a VM disk image on GlusterFS volume is

   .. parsed-literal::

      URI:
      gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]

      JSON:
      'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
                                       "server":[{"type":"tcp","host":"...","port":"..."},
                                                 {"type":"unix","socket":"..."}]}}'

   Example

   .. parsed-literal::

      URI:
      |qemu_system| --drive file=gluster://192.0.2.1/testvol/a.img,
                                     file.debug=9,file.logfile=/var/log/qemu-gluster.log

      JSON:
      |qemu_system| 'json:{"driver":"qcow2",
                                "file":{"driver":"gluster",
                                         "volume":"testvol","path":"a.img",
                                         "debug":9,"logfile":"/var/log/qemu-gluster.log",
                                         "server":[{"type":"tcp","host":"1.2.3.4","port":24007},
                                                   {"type":"unix","socket":"/var/run/glusterd.socket"}]}}'
      |qemu_system| -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
                                            file.debug=9,file.logfile=/var/log/qemu-gluster.log,
                                            file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
                                            file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket

   See also http://www.gluster.org.

``HTTP/HTTPS/FTP/FTPS``
   QEMU supports read-only access to files accessed over http(s) and
   ftp(s).

   Syntax using a single filename:

   ::

      <protocol>://[<username>[:<password>]@]<host>/<path>

   where:

   ``protocol``
      'http', 'https', 'ftp', or 'ftps'.

   ``username``
      Optional username for authentication to the remote server.

   ``password``
      Optional password for authentication to the remote server.

   ``host``
      Address of the remote server.

   ``path``
      Path on the remote server, including any query string.

   The following options are also supported:

   ``url``
      The full URL when passing options to the driver explicitly.

   ``readahead``
      The amount of data to read ahead with each range request to the
      remote server. This value may optionally have the suffix 'T', 'G',
      'M', 'K', 'k' or 'b'. If it does not have a suffix, it will be
      assumed to be in bytes. The value must be a multiple of 512 bytes.
      It defaults to 256k.

   ``sslverify``
      Whether to verify the remote server's certificate when connecting
      over SSL. It can have the value 'on' or 'off'. It defaults to
      'on'.

   ``cookie``
      Send this cookie (it can also be a list of cookies separated by
      ';') with each outgoing request. Only supported when using
      protocols such as HTTP which support cookies, otherwise ignored.

   ``timeout``
      Set the timeout in seconds of the CURL connection. This timeout is
      the time that CURL waits for a response from the remote server to
      get the size of the image to be downloaded. If not set, the
      default timeout of 5 seconds is used.

   Note that when passing options to qemu explicitly, ``driver`` is the
   value of <protocol>.

   Example: boot from a remote Fedora 20 live ISO image

   .. parsed-literal::

      |qemu_system_x86| --drive media=cdrom,file=https://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly

      |qemu_system_x86| --drive media=cdrom,file.driver=http,file.url=http://archives.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly

   Example: boot from a remote Fedora 20 cloud image using a local
   overlay for writes, copy-on-read, and a readahead of 64k

   .. parsed-literal::

      qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"http",, "file.url":"http://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2

      |qemu_system_x86| -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on

   Example: boot from an image stored on a VMware vSphere server with a
   self-signed certificate using a local overlay for writes, a readahead
   of 64k and a timeout of 10 seconds.

   .. parsed-literal::

      qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"https",, "file.url":"https://user:password@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10}' /tmp/test.qcow2

      |qemu_system_x86| -drive file=/tmp/test.qcow2
Commit	Line	Data
bf87bef0 PM	1
	2	In addition to using normal file images for the emulated storage
	3	devices, QEMU can also use networked resources such as iSCSI devices.
	4	These are specified using a special URL syntax.
	5
	6	``iSCSI``
	7	iSCSI support allows QEMU to access iSCSI resources directly and use
	8	as images for the guest storage. Both disk and cdrom images are
	9	supported.
	10
	11	Syntax for specifying iSCSI LUNs is
	12	"iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>"
	13
	14	By default qemu will use the iSCSI initiator-name
	15	'iqn.2008-11.org.linux-kvm[:<name>]' but this can also be set from
	16	the command line or a configuration file.
	17
	18	Since version Qemu 2.4 it is possible to specify a iSCSI request
	19	timeout to detect stalled requests and force a reestablishment of the
	20	session. The timeout is specified in seconds. The default is 0 which
	21	means no timeout. Libiscsi 1.15.0 or greater is required for this
	22	feature.
	23
	24	Example (without authentication):
	25
	26	.. parsed-literal::
	27
	28	\|qemu_system\| -iscsi initiator-name=iqn.2001-04.com.example:my-initiator \
	29	-cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
	30	-drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
	31
	32	Example (CHAP username/password via URL):
	33
	34	.. parsed-literal::
	35
	36	\|qemu_system\| -drive file=iscsi://user%password@192.0.2.1/iqn.2001-04.com.example/1
	37
	38	Example (CHAP username/password via environment variables):
	39
	40	.. parsed-literal::
	41
	42	LIBISCSI_CHAP_USERNAME="user" \
	43	LIBISCSI_CHAP_PASSWORD="password" \
	44	\|qemu_system\| -drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1
	45
	46	``NBD``
	47	QEMU supports NBD (Network Block Devices) both using TCP protocol as
	48	well as Unix Domain Sockets. With TCP, the default port is 10809.
	49
	50	Syntax for specifying a NBD device using TCP, in preferred URI form:
	51	"nbd://<server-ip>[:<port>]/[<export>]"
	52
	53	Syntax for specifying a NBD device using Unix Domain Sockets;
	54	remember that '?' is a shell glob character and may need quoting:
	55	"nbd+unix:///[<export>]?socket=<domain-socket>"
	56
	57	Older syntax that is also recognized:
	58	"nbd:<server-ip>:<port>[:exportname=<export>]"
	59
	60	Syntax for specifying a NBD device using Unix Domain Sockets
	61	"nbd:unix:<domain-socket>[:exportname=<export>]"
	62
	63	Example for TCP
	64
65	.. parsed-literal::
66
67	\|qemu_system\| --drive file=nbd:192.0.2.1:30000
68
69	Example for Unix Domain Sockets
70
71	.. parsed-literal::
72
73	\|qemu_system\| --drive file=nbd:unix:/tmp/nbd-socket
74
75	``SSH``
76	QEMU supports SSH (Secure Shell) access to remote disks.
77
78	Examples:
79
80	.. parsed-literal::
81
82	\|qemu_system\| -drive file=ssh://user@host/path/to/disk.img
83	\|qemu_system\| -drive file.driver=ssh,file.user=user,file.host=host,file.port=22,file.path=/path/to/disk.img
84
85	Currently authentication must be done using ssh-agent. Other
86	authentication methods may be supported in future.
87
88	``Sheepdog``
89	Sheepdog is a distributed storage system for QEMU. QEMU supports
90	using either local sheepdog devices or remote networked devices.
91
92	Syntax for specifying a sheepdog device
93
94	::
95
96	sheepdog[+tcp\|+unix]://[host:port]/vdiname[?socket=path][#snapid\|#tag]
97
98	Example
99
100	.. parsed-literal::
101
102	\|qemu_system\| --drive file=sheepdog://192.0.2.1:30000/MyVirtualMachine
103
104	See also https://sheepdog.github.io/sheepdog/.
105
106	``GlusterFS``
107	GlusterFS is a user space distributed file system. QEMU supports the
108	use of GlusterFS volumes for hosting VM disk images using TCP, Unix
109	Domain Sockets and RDMA transport protocols.
110
111	Syntax for specifying a VM disk image on GlusterFS volume is
112
113	.. parsed-literal::
114
115	URI:
116	gluster[+type]://[host[:port]]/volume/path[?socket=...][,debug=N][,logfile=...]
117
118	JSON:
119	'json:{"driver":"qcow2","file":{"driver":"gluster","volume":"testvol","path":"a.img","debug":N,"logfile":"...",
120	"server":[{"type":"tcp","host":"...","port":"..."},
121	{"type":"unix","socket":"..."}]}}'
122
123	Example
124
125	.. parsed-literal::
126
127	URI:
128	\|qemu_system\| --drive file=gluster://192.0.2.1/testvol/a.img,
129	file.debug=9,file.logfile=/var/log/qemu-gluster.log
130
131	JSON:
132	\|qemu_system\| 'json:{"driver":"qcow2",
133	"file":{"driver":"gluster",
134	"volume":"testvol","path":"a.img",
135	"debug":9,"logfile":"/var/log/qemu-gluster.log",
136	"server":[{"type":"tcp","host":"1.2.3.4","port":24007},
137	{"type":"unix","socket":"/var/run/glusterd.socket"}]}}'
138	\|qemu_system\| -drive driver=qcow2,file.driver=gluster,file.volume=testvol,file.path=/path/a.img,
139	file.debug=9,file.logfile=/var/log/qemu-gluster.log,
140	file.server.0.type=tcp,file.server.0.host=1.2.3.4,file.server.0.port=24007,
141	file.server.1.type=unix,file.server.1.socket=/var/run/glusterd.socket
142
143	See also http://www.gluster.org.
144
145	``HTTP/HTTPS/FTP/FTPS``
146	QEMU supports read-only access to files accessed over http(s) and
147	ftp(s).
148
149	Syntax using a single filename:
150
151	::
152
153	<protocol>://[<username>[:<password>]@]<host>/<path>
154
155	where:
156
157	``protocol``
158	'http', 'https', 'ftp', or 'ftps'.
159
160	``username``
161	Optional username for authentication to the remote server.
162
163	``password``
164	Optional password for authentication to the remote server.
165
166	``host``
167	Address of the remote server.
168
169	``path``
170	Path on the remote server, including any query string.
171
172	The following options are also supported:
173
174	``url``
175	The full URL when passing options to the driver explicitly.
176
177	``readahead``
178	The amount of data to read ahead with each range request to the
179	remote server. This value may optionally have the suffix 'T', 'G',
180	'M', 'K', 'k' or 'b'. If it does not have a suffix, it will be
181	assumed to be in bytes. The value must be a multiple of 512 bytes.
182	It defaults to 256k.
183
184	``sslverify``
185	Whether to verify the remote server's certificate when connecting
186	over SSL. It can have the value 'on' or 'off'. It defaults to
187	'on'.
188
189	``cookie``
190	Send this cookie (it can also be a list of cookies separated by
191	';') with each outgoing request. Only supported when using
192	protocols such as HTTP which support cookies, otherwise ignored.
193
194	``timeout``
195	Set the timeout in seconds of the CURL connection. This timeout is
196	the time that CURL waits for a response from the remote server to
197	get the size of the image to be downloaded. If not set, the
198	default timeout of 5 seconds is used.
199
200	Note that when passing options to qemu explicitly, ``driver`` is the
201	value of <protocol>.
202
203	Example: boot from a remote Fedora 20 live ISO image
204
205	.. parsed-literal::
206
207	\|qemu_system_x86\| --drive media=cdrom,file=https://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
208
209	\|qemu_system_x86\| --drive media=cdrom,file.driver=http,file.url=http://archives.fedoraproject.org/pub/fedora/linux/releases/20/Live/x86_64/Fedora-Live-Desktop-x86_64-20-1.iso,readonly
210
211	Example: boot from a remote Fedora 20 cloud image using a local
212	overlay for writes, copy-on-read, and a readahead of 64k
213
214	.. parsed-literal::
215
216	qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"http",, "file.url":"http://archives.fedoraproject.org/pub/archive/fedora/linux/releases/20/Images/x86_64/Fedora-x86_64-20-20131211.1-sda.qcow2",, "file.readahead":"64k"}' /tmp/Fedora-x86_64-20-20131211.1-sda.qcow2
217
218	\|qemu_system_x86\| -drive file=/tmp/Fedora-x86_64-20-20131211.1-sda.qcow2,copy-on-read=on
219
220	Example: boot from an image stored on a VMware vSphere server with a
221	self-signed certificate using a local overlay for writes, a readahead
222	of 64k and a timeout of 10 seconds.
223
224	.. parsed-literal::
225
226	qemu-img create -f qcow2 -o backing_file='json:{"file.driver":"https",, "file.url":"https://user:password@vsphere.example.com/folder/test/test-flat.vmdk?dcPath=Datacenter&dsName=datastore1",, "file.sslverify":"off",, "file.readahead":"64k",, "file.timeout":10}' /tmp/test.qcow2
227
228	\|qemu_system_x86\| -drive file=/tmp/test.qcow2