diff --git a/docs/formatnetwork.html b/docs/formatnetwork.html index e951cd7885..321acf5583 100644 --- a/docs/formatnetwork.html +++ b/docs/formatnetwork.html @@ -114,17 +114,41 @@

Network XML format

+

This page provides an introduction to the network XML format. For background information on the concepts referred to here, consult the network driver architecture page.

-

Element and attribute overview

+

+ Element and attribute overview +

The root element required for all virtual networks is named network and has no attributes. + The network XML format is available since 0.3.0

-

General metadata

+

+ General metadata +

The first elements provide basic metadata about the virtual network. @@ -139,12 +163,14 @@ consist only of alpha-numeric characters and is required to be unique within the scope of a single host. It is used to form the filename for storing the persistent - configuration file.

uuid
The content of the uuid element provides + configuration file. Since 0.3.0
uuid
The content of the uuid element provides a globally unique identifier for the virtual network. The format must be RFC 4122 compliant, eg 3e3fce45-4f53-4fa7-bb32-11f34168b82b. If omitted when defining/creating a new network, a random - UUID is generated.
-

Connectivity

+ UUID is generated. Since 0.3.0 +

+ Connectivity +

The next set of elements control how a virtual network is provided connectivity to the physical LAN (if at all). @@ -152,7 +178,7 @@ 

         ...
         <bridge name="virbr0" />
-	<forward type="nat"/>
+	<forward mode="nat" dev="eth0"/>
 	...
bridge
The name attribute on the bridge element defines the name of a bridge device which will be used to construct @@ -161,18 +187,22 @@ may also be connected to the LAN. It is recommended that bridge device names started with the prefix vir, but the name virbr0 is reserved for the "default" virtual network. - This element should always be provided when defining a new network + This element should always be provided when defining a new network. + Since 0.3.0
forward
Inclusion of the forward element indicates that the virtual network is to be connected to the physical LAN. If no attributes are set, NAT forwarding will be used for connectivity. Firewall rules will allow forwarding to any other network device whether ethernet, wireless, dialup, or VPN. If the dev attribute is set, the firewall rules will restrict forwarding to the named - device only. If the type attribute is set to route + device only. If the mode attribute is set to route then the traffic will not have NAT applied. This presumes that the local LAN router has suitable routing table entries to return traffic - to this host.
-

Addressing

+ to this host. Since 0.3.0; 'mode' attribute since + 0.4.2 +

+ Addressing +

The final set of elements define the IPv4 address range available, and optionally enable DHCP sevices. @@ -190,19 +220,24 @@ device associated with the virtual network. To the guests this address will be their default route. The netmask attribute defines the significant bits of the network address, - again specified in dotted-decimal format. + again specified in dotted-decimal format. Since 0.3.0

dhcp
Immediately within the ip element there is an optional dhcp element. The presence of this element enables DHCP services on the virtual network. It will further contain one or more range elements. + Since 0.3.0
range
The start and end attributes on the range element specify the boundaries of a pool of IPv4 addresses to be provided to DHCP clients. These two addresses must lie within the scope of the network defined on the parent - ip element. + ip element. Since 0.3.0
-

Example configuration

-

NAT based network

+

+ Example configuration +

+

+ NAT based network +

This example is the so called "default" virtual network. It is provided and enabled out-of-the-box for all libvirt installations. @@ -223,7 +258,9 @@ </dhcp> </ip> </network> -

Routed network config

+

+ Routed network config +

This is a variant on the default network which routes traffic from the virtual network to the LAN without applying any NAT. @@ -243,7 +280,9 @@ </dhcp> </ip> </network> -

Isolated network config

+

+ Isolated network config +

This variant provides a completely isolated private network for guests. The guests can talk to each other, and the host diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in index d3da000321..9c46a8946a 100644 --- a/docs/formatnetwork.html.in +++ b/docs/formatnetwork.html.in @@ -2,20 +2,24 @@

Network XML format

+ +

This page provides an introduction to the network XML format. For background information on the concepts referred to here, consult the network driver architecture page.

-

Element and attribute overview

+

Element and attribute overview

The root element required for all virtual networks is named network and has no attributes. + The network XML format is available since 0.3.0

-

General metadata

+

General metadata

The first elements provide basic metadata about the virtual @@ -35,16 +39,16 @@ consist only of alpha-numeric characters and is required to be unique within the scope of a single host. It is used to form the filename for storing the persistent - configuration file. + configuration file. Since 0.3.0

uuid
The content of the uuid element provides a globally unique identifier for the virtual network. The format must be RFC 4122 compliant, eg 3e3fce45-4f53-4fa7-bb32-11f34168b82b. If omitted when defining/creating a new network, a random - UUID is generated.
+ UUID is generated. Since 0.3.0 -

Connectivity

+

Connectivity

The next set of elements control how a virtual network is @@ -54,7 +58,7 @@ 

         ...
         <bridge name="virbr0" />
-	<forward type="nat"/>
+	<forward mode="nat" dev="eth0"/>
 	...
@@ -66,7 +70,8 @@ may also be connected to the LAN. It is recommended that bridge device names started with the prefix vir, but the name virbr0 is reserved for the "default" virtual network. - This element should always be provided when defining a new network + This element should always be provided when defining a new network. + Since 0.3.0
forward
Inclusion of the forward element indicates that @@ -75,13 +80,14 @@ Firewall rules will allow forwarding to any other network device whether ethernet, wireless, dialup, or VPN. If the dev attribute is set, the firewall rules will restrict forwarding to the named - device only. If the type attribute is set to route + device only. If the mode attribute is set to route then the traffic will not have NAT applied. This presumes that the local LAN router has suitable routing table entries to return traffic - to this host.
+ to this host. Since 0.3.0; 'mode' attribute since + 0.4.2
-

Addressing

+

Addressing

The final set of elements define the IPv4 address range available, @@ -104,26 +110,27 @@ device associated with the virtual network. To the guests this address will be their default route. The netmask attribute defines the significant bits of the network address, - again specified in dotted-decimal format. + again specified in dotted-decimal format. Since 0.3.0

dhcp
Immediately within the ip element there is an optional dhcp element. The presence of this element enables DHCP services on the virtual network. It will further contain one or more range elements. + Since 0.3.0
range
The start and end attributes on the range element specify the boundaries of a pool of IPv4 addresses to be provided to DHCP clients. These two addresses must lie within the scope of the network defined on the parent - ip element. + ip element. Since 0.3.0
-

Example configuration

+

Example configuration

-

NAT based network

+

NAT based network

This example is the so called "default" virtual network. It is @@ -147,7 +154,7 @@ </ip> </network> -

Routed network config

+

Routed network config

This is a variant on the default network which routes traffic @@ -170,7 +177,7 @@ </ip> </network> -

Isolated network config

+

Isolated network config

This variant provides a completely isolated private network diff --git a/docs/formatstorage.html b/docs/formatstorage.html index df139c064e..4f0027bcd2 100644 --- a/docs/formatstorage.html +++ b/docs/formatstorage.html @@ -115,171 +115,300 @@

Storage pool and volume XML format

-

+ Example configuration + + +

Storage pool XML -

+

-Although all storage pool backends share the same public APIs and -XML format, they have varying levels of capabilities. Some may -allow creation of volumes, others may only allow use of pre-existing -volumes. Some may have constraints on volume size, or placement. -

-

The is the top level tag for a storage pool document is 'pool'. It has -a single attribute type, which is one of dir, -fs,netfs,disk,iscsi, -logical. This corresponds to the storage backend drivers -listed further along in this document. -

-

- First level elements -

-
name
Providing a name for the pool which is unique to the host. -This is mandatory when defining a pool
uuid
Providing an identifier for the pool which is globally unique. -This is optional when defining a pool, a UUID will be generated if -omitted
allocation
Providing the total storage allocation for the pool. This may -be larger than the sum of the allocation of all volumes due to -metadata overhead. This value is in bytes. This is not applicable -when creating a pool.
capacity
Providing the total storage capacity for the pool. Due to -underlying device constraints it may not be possible to use the -full capacity for storage volumes. This value is in bytes. This -is not applicable when creating a pool.
available
Providing the free space available for allocating new volumes -in the pool. Due to underlying device constraints it may not be -possible to allocate the entire free space to a single volume. -This value is in bytes. This is not applicable when creating a -pool.
source
Provides information about the source of the pool, such as -the underlying host devices, or remote server
target
Provides information about the representation of the pool -on the local host.
-

- Source elements -

-
device
Provides the source for pools backed by physical devices. -May be repeated multiple times depending on backend driver. Contains -a single attribute path which is the fully qualified -path to the block device node.
directory
Provides the source for pools backed by directories. May -only occur once. Contains a single attribute path -which is the fully qualified path to the block device node.
host
Provides the source for pools backed by storage from a -remote server. Will be used in combination with a directory -or device element. Contains an attribute name -which is the hostname or IP address of the server. May optionally -contain a port attribute for the protocol specific -port number.
format
Provides information about the format of the pool. This -contains a single attribute type whose value is -backend specific. This is typically used to indicate filesystem -type, or network filesystem type, or partition table type, or -LVM metadata type. All drivers are required to have a default -value for this, so it is optional.
-

- Target elements -

-
path
Provides the location at which the pool will be mapped into -the local filesystem namespace. For a filesystem/directory based -pool it will be the name of the directory in which volumes will -be created. For device based pools it will be the name of the directory in which -devices nodes exist. For the latter /dev/ may seem -like the logical choice, however, devices nodes there are not -guaranteed stable across reboots, since they are allocated on -demand. It is preferable to use a stable location such as one -of the /dev/disk/by-{path,id,uuid,label locations. -
permissions
Provides information about the default permissions to use -when creating volumes. This is currently only useful for directory -or filesystem based pools, where the volumes allocated are simple -files. For pools where the volumes are device nodes, the hotplug -scripts determine permissions. It contains 4 child elements. The -mode element contains the octal permission set. The -owner element contains the numeric user ID. The group -element contains the numeric group ID. The label element -contains the MAC (eg SELinux) label string. -
-

- Device extents -

+ Although all storage pool backends share the same public APIs and + XML format, they have varying levels of capabilities. Some may + allow creation of volumes, others may only allow use of pre-existing + volumes. Some may have constraints on volume size, or placement. +

-If a storage pool exposes information about its underlying -placement / allocation scheme, the device element -within the source element may contain information -about its available extents. Some pools have a constraint that -a volume must be allocated entirely within a single constraint -(eg disk partition pools). Thus the extent information allows an -application to determine the maximum possible size for a new -volume -

-

-For storage pools supporting extent information, within each -device element there will be zero or more freeExtent -elements. Each of these elements contains two attributes, start -and end which provide the boundaries of the extent on the -device, measured in bytes. -

+ The is the top level tag for a storage pool document is 'pool'. It has + a single attribute type, which is one of dir, + fs,netfs,disk,iscsi, + logical. This corresponds to the storage backend drivers + listed further along in this document. + The storage pool XML format is available since 0.4.1 +

- Storage volume XML + General metadata +

+ 
+      <pool type="iscsi">
+        <name>virtimages</name>
+        <uuid>3e3fce45-4f53-4fa7-bb32-11f34168b82b</uuid>
+        <allocation>10000000</allocation>
+        <capacity>50000000</capacity>
+        <available>40000000</available>
+        ...
+
name
Providing a name for the pool which is unique to the host. + This is mandatory when defining a pool. Since 0.4.1
uuid
Providing an identifier for the pool which is globally unique. + This is optional when defining a pool, a UUID will be generated if + omitted. Since 0.4.1
allocation
Providing the total storage allocation for the pool. This may + be larger than the sum of the allocation of all volumes due to + metadata overhead. This value is in bytes. This is not applicable + when creating a pool. Since 0.4.1
capacity
Providing the total storage capacity for the pool. Due to + underlying device constraints it may not be possible to use the + full capacity for storage volumes. This value is in bytes. This + is not applicable when creating a pool. Since 0.4.1
available
Providing the free space available for allocating new volumes + in the pool. Due to underlying device constraints it may not be + possible to allocate the entire free space to a single volume. + This value is in bytes. This is not applicable when creating a + pool. Since 0.4.1
+

+ Source elements

-A storage volume will be either a file or a device node. -

-

- First level elements -

-
name
Providing a name for the pool which is unique to the host. -This is mandatory when defining a pool
uuid
Providing an identifier for the pool which is globally unique. -This is optional when defining a pool, a UUID will be generated if -omitted
allocation
Providing the total storage allocation for the volume. This -may be smaller than the logical capacity if the volume is sparsely -allocated. It may also be larger than the logical capacity if the -volume has substantial metadata overhead. This value is in bytes. -If omitted when creating a volume, the volume will be fully -allocated at time of creation. If set to a value smaller than the -capacity, the pool has the option of deciding -to sparsely allocate a volume. It does not have to honour requests -for sparse allocation though.
capacity
Providing the logical capacity for the volume. This value is -in bytes. This is compulsory when creating a volume
source
Provides information about the underlying storage allocation -of the volume. This may not be available for some pool types.
target
Provides information about the representation of the volume -on the local host.
-

+ A single source element is contained within the top level + pool element. This tag is used to describe the source of + the storage pool. It can contain the following child elements: +

+ 
+        ...
+        <source>
+          <host name="iscsi.example.com"/>
+          <device path="demo-target"/>
+        </source>
+	...
+
device
Provides the source for pools backed by physical devices. + May be repeated multiple times depending on backend driver. Contains + a single attribute path which is the fully qualified + path to the block device node. Since 0.4.1
directory
Provides the source for pools backed by directories. May + only occur once. Contains a single attribute path + which is the fully qualified path to the block device node. + Since 0.4.1
host
Provides the source for pools backed by storage from a + remote server. Will be used in combination with a directory + or device element. Contains an attribute name + which is the hostname or IP address of the server. May optionally + contain a port attribute for the protocol specific + port number. Since 0.4.1
format
Provides information about the format of the pool. This + contains a single attribute type whose value is + backend specific. This is typically used to indicate filesystem + type, or network filesystem type, or partition table type, or + LVM metadata type. All drivers are required to have a default + value for this, so it is optional. Since 0.4.1
+

+ Target elements +

+

+ A single target element is contained within the top level + pool element. This tag is used to describe the mapping of + the storage pool into the host filesystem. It can contain the following + child elements: +

+ 
+        ...
+        <target>
+          <path>/dev/disk/by-path</path>
+          <permissions>
+            <owner>0744</owner>
+            <group>0744</group>
+            <mode>0744</mode>
+            <label>virt_image_t</label>
+          </permissions>
+        </target>
+      </pool>
+
path
Provides the location at which the pool will be mapped into + the local filesystem namespace. For a filesystem/directory based + pool it will be the name of the directory in which volumes will + be created. For device based pools it will be the name of the directory in which + devices nodes exist. For the latter /dev/ may seem + like the logical choice, however, devices nodes there are not + guaranteed stable across reboots, since they are allocated on + demand. It is preferable to use a stable location such as one + of the /dev/disk/by-{path,id,uuid,label locations. + Since 0.4.1 +
permissions
Provides information about the default permissions to use + when creating volumes. This is currently only useful for directory + or filesystem based pools, where the volumes allocated are simple + files. For pools where the volumes are device nodes, the hotplug + scripts determine permissions. It contains 4 child elements. The + mode element contains the octal permission set. The + owner element contains the numeric user ID. The group + element contains the numeric group ID. The label element + contains the MAC (eg SELinux) label string. + Since 0.4.1 +
+

+ Device extents +

+

+ If a storage pool exposes information about its underlying + placement / allocation scheme, the device element + within the source element may contain information + about its available extents. Some pools have a constraint that + a volume must be allocated entirely within a single constraint + (eg disk partition pools). Thus the extent information allows an + application to determine the maximum possible size for a new + volume +

+

+ For storage pools supporting extent information, within each + device element there will be zero or more freeExtent + elements. Each of these elements contains two attributes, start + and end which provide the boundaries of the extent on the + device, measured in bytes. Since 0.4.1 +

+

+ Storage volume XML +

+

+ A storage volume will be either a file or a device node. + The storage volume XML format is available since 0.4.1 +

+

+ General metadata +

+ 
+      <volume type="file">
+	<name>sparse.img</name>
+	<key>/var/lib/xen/images/sparse.img</key>
+        <allocation>0</allocation>
+	<capacity unit="T">1</capacity>
+        ...
+
name
Providing a name for the volume which is unique to the pool. + This is mandatory when defining a volume. Since 0.4.1
key
Providing an identifier for the volume which is globally unique. + This is optional when defining a volume, a key will be generated if + omitted. Since 0.4.1
allocation
Providing the total storage allocation for the volume. This + may be smaller than the logical capacity if the volume is sparsely + allocated. It may also be larger than the logical capacity if the + volume has substantial metadata overhead. This value is in bytes. + If omitted when creating a volume, the volume will be fully + allocated at time of creation. If set to a value smaller than the + capacity, the pool has the option of deciding + to sparsely allocate a volume. It does not have to honour requests + for sparse allocation though. Since 0.4.1
capacity
Providing the logical capacity for the volume. This value is + in bytes. This is compulsory when creating a volume. + Since 0.4.1
source
Provides information about the underlying storage allocation + of the volume. This may not be available for some pool types. + Since 0.4.1
target
Provides information about the representation of the volume + on the local host. Since 0.4.1
+

Target elements -

-
path
Provides the location at which the pool will be mapped into -the local filesystem namespace. For a filesystem/directory based -pool it will be the name of the directory in which volumes will -be created. For device based pools it will be the name of the directory in which -devices nodes exist. For the latter /dev/ may seem -like the logical choice, however, devices nodes there are not -guaranteed stable across reboots, since they are allocated on -demand. It is preferable to use a stable location such as one -of the /dev/disk/by-{path,id,uuid,label locations. -
format
Provides information about the pool specific volume format. -For disk pools it will provide the partition type. For filesystem -or directory pools it will provide the file format type, eg cow, -qcow, vmdk, raw. If omitted when creating a volume, the pool's -default format will be used. The actual format is specified via -the type. Consult the pool-specific docs for the -list of valid values.
permissions
Provides information about the default permissions to use -when creating volumes. This is currently only useful for directory -or filesystem based pools, where the volumes allocated are simple -files. For pools where the volumes are device nodes, the hotplug -scripts determine permissions. It contains 4 child elements. The -mode element contains the octal permission set. The -owner element contains the numeric user ID. The group -element contains the numeric group ID. The label element -contains the MAC (eg SELinux) label string. -
+ +

+ A single target element is contained within the top level + volume element. This tag is used to describe the mapping of + the storage volume into the host filesystem. It can contain the following + child elements: +

+ 
+        ...
+	<target>
+          <path>/var/lib/virt/images/sparse.img</path>
+          <permissions>
+            <owner>0744</owner>
+            <group>0744</group>
+            <mode>0744</mode>
+            <label>virt_image_t</label>
+          </permissions>
+	</target>
+      </volume>
+
path
Provides the location at which the pool will be mapped into + the local filesystem namespace. For a filesystem/directory based + pool it will be the name of the directory in which volumes will + be created. For device based pools it will be the name of the directory in which + devices nodes exist. For the latter /dev/ may seem + like the logical choice, however, devices nodes there are not + guaranteed stable across reboots, since they are allocated on + demand. It is preferable to use a stable location such as one + of the /dev/disk/by-{path,id,uuid,label locations. + Since 0.4.1 +
format
Provides information about the pool specific volume format. + For disk pools it will provide the partition type. For filesystem + or directory pools it will provide the file format type, eg cow, + qcow, vmdk, raw. If omitted when creating a volume, the pool's + default format will be used. The actual format is specified via + the type. Consult the pool-specific docs for the + list of valid values. Since 0.4.1
permissions
Provides information about the default permissions to use + when creating volumes. This is currently only useful for directory + or filesystem based pools, where the volumes allocated are simple + files. For pools where the volumes are device nodes, the hotplug + scripts determine permissions. It contains 4 child elements. The + mode element contains the octal permission set. The + owner element contains the numeric user ID. The group + element contains the numeric group ID. The label element + contains the MAC (eg SELinux) label string. + Since 0.4.1 +
+

+ Example configuration +

+

+ Here are a couple of examples, for a more complete set demonstrating + every type of storage pool, consult the storage driver page +

+

+ File based storage pool +

+ 
+      <pool type="dir">
+        <name>virtimages</name>
+        <target>
+          <path>/var/lib/virt/images</path>
+        </target>
+      </pool>
+

+ iSCSI based storage pool +

+ 
+      <pool type="iscsi">
+        <name>virtimages</name>
+        <source>
+          <host name="iscsi.example.com"/>
+          <device path="demo-target"/>
+        </source>
+        <target>
+          <path>/dev/disk/by-path</path>
+        </target>
+      </pool>
+

+ Storage volume +

+ 
+      <volume type="file">
+	<name>sparse.img</name>
+	<allocation>0</allocation>
+	<capacity unit="T">1</capacity>
+	<target>
+          <path>/var/lib/virt/images/sparse.img</path>
+          <permissions>
+            <owner>0744</owner>
+            <group>0744</group>
+            <mode>0744</mode>
+            <label>virt_image_t</label>
+          </permissions>
+	</target>
+      </volume>
- + + + + + + + + + +