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diff --git a/docs/system/device-url-syntax.rst.inc b/docs/system/device-url-syntax.rst.inc new file mode 100644 index 0000000000..88d7a372a7 --- /dev/null +++ b/docs/system/device-url-syntax.rst.inc @@ -0,0 +1,228 @@ + +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 |