diff --git a/docs/en-US/host-allocation.xml b/docs/en-US/host-allocation.xml
index f5bc53c7fbf..d287856ecf9 100644
--- a/docs/en-US/host-allocation.xml
+++ b/docs/en-US/host-allocation.xml
@@ -28,5 +28,4 @@
&PRODUCT; administrators can specify that certain hosts should have a preference for particular types of guest instances. For example, an administrator could state that a host should have a preference to run Windows guests. The default host allocator will attempt to place guests of that OS type on such hosts first. If no such host is available, the allocator will place the instance wherever there is sufficient physical capacity.
Both vertical and horizontal allocation is allowed. Vertical allocation consumes all the resources of a given host before allocating any guests on a second host. This reduces power consumption in the cloud. Horizontal allocation places a guest on each host in a round-robin fashion. This may yield better performance to the guests in some cases. &PRODUCT; also allows an element of CPU over-provisioning as configured by the administrator. Over-provisioning allows the administrator to commit more CPU cycles to the allocated guests than are actually available from the hardware.
&PRODUCT; also provides a pluggable interface for adding new allocators. These custom allocators can provide any policy the administrator desires.
-
diff --git a/docs/en-US/over-provisioning-service-offering-limits.xml b/docs/en-US/over-provisioning-service-offering-limits.xml
index 64a162745e5..449606d1aa1 100644
--- a/docs/en-US/over-provisioning-service-offering-limits.xml
+++ b/docs/en-US/over-provisioning-service-offering-limits.xml
@@ -23,9 +23,119 @@
-->
- Over-Provisioning and Service Offering Limits
- &PRODUCT; performs CPU over-provisioning based on an over-provisioning ratio configured by the administrator. This is defined by the cpu.overprovisioning.factor global configuration variable.
- &PRODUCT; performs CPU over-provisioning based on an over-provisioning ratio configured by the administrator. This is defined by the cpu.overprovisioning.factor global configuration variable
+ Over-Provisioning and Service Offering Limits
+ (Supported for XenServer, KVM, and VMware)
+ CPU and memory (RAM) over-provisioning factors can be set for each cluster to change the
+ number of VMs that can run on each host in the cluster. This helps optimize the use of
+ resources. By increasing the over-provisioning ratio, more resource capacity will be used. If
+ the ratio is set to 1, no over-provisioning is done.
+ The administrator can also set global default over-provisioning ratios
+ in the cpu.overprovisioning.factor and mem.overprovisioning.factor global configuration variables.
+
+ In XenServer, due to a constraint of this hypervisor, you can not use an
+ over-provisioning factor greater than 4.
+
+ Over-provisioning ratios are dynamically substituted in &PRODUCT;'s capacity
+ calculations. For example:
+ Capacity = 2 GB
+ Over-provisioning factor = 2
+ Capacity after over-provisioning = 4 GB
+ With this configuration, suppose you deploy 3 VMs of 1 GB each:
+ Used = 3 GB
+ Free = 1 GB
+ The administrator can specify a memory over-provisioning ratio, and can specify both CPU and
+ memory over-provisioning ratios on a per-cluster basis.
+ In any given cloud, the optimum number of VMs for each host is affected by such things
+ as the hypervisor, storage, and hardware configuration. These may be different for each
+ cluster in the same cloud. A single global over-provisioning setting could not provide the
+ best utilization for all the different clusters in the cloud. It had to be set for the
+ lowest common denominator. The new per-cluster setting provides a finer granularity for
+ better utilization of resources, no matter where the &PRODUCT; placement algorithm decides
+ to place a VM.
+ The overprovisioning settings can be used along with dedicated resources (assigning a
+ specific cluster to an account) to effectively offer different levels of service to
+ different accounts. For example, an account paying for a more expensive level of service
+ could be assigned to a dedicated cluster with an over-provisioning ratio of 1, and a
+ lower-paying account to a cluster with a ratio of 2.
+ When a new host is added to a cluster, &PRODUCT; will assume the host has the
+ capability to perform the CPU and RAM over-provisioning which is configured for that
+ cluster. It is up to the administrator to be sure the host is actually suitable for the
+ level of over-provisioning which has been set.
+
+ Requirements for Over-Provisioning
+ Several prerequisites are required in order for over-provisioning to function
+ properly. The feature is dependent on the OS type, hypervisor capabilities, and certain
+ scripts. It is the administrator's responsibility to ensure that these requirements are
+ met.
+
+ Balloon Driver
+ All VMs should have a balloon driver installed in them. The hypervisor
+ communicates with the balloon driver to free up and make the memory available to a
+ VM.
+
+ XenServer
+ The balloon driver can be found as a part of xen pv or PVHVM drivers. The xen
+ pvhvm drivers are included in upstream linux kernels 2.6.36+.
+
+
+ VMware
+ The balloon driver can be found as a part of the VMware tools. All the VMs that
+ are deployed in a over-provisioned cluster should have the VMware tools
+ installed.
+
+
+ KVM
+ All VMs are required to support the virtio drivers. These drivers are installed
+ in all Linux kernel versions 2.6.25 and greater. The administrator must set
+ CONFIG_VIRTIO_BALLOON=y in the virtio configuration.
+
+
+
+ Hypervisor capabilities
+ The hypervisor must be capable of using the memory ballooning.
+
+ XenServer
+ The DMC (Dynamic Memory Control) capability of the hypervisor should be enabled.
+ Only XenServer Advanced and above versions have this feature.
+
+
+ VMware, KVM
+ Memory ballooning is supported by default.
+
+
+
+
+ Setting Over-Provisioning Ratios
+ The root admin can set CPU and RAM over-provisioning ratios when creating a cluster.
+ The ratios can also be modified later for an existing cluster. In this case, only VMs
+ deployed after the change are affected by the new setting.
+
+
+ Log in as administrator to the &PRODUCT; UI.
+
+
+ In the left navigation bar, click Infrastructure.
+
+
+ Under Clusters, click View All.
+
+
+ Click Add Cluster.
+
+
+ Fill in your desired over-provisioning multipliers in the fields CPU overcommit
+ ratio and RAM overcommit ratio. The value of 1 which is intially shown in these
+ fields is the default value: over-provisioning is turned off by default.
+
+ In XenServer, due to a constraint of this hypervisor, you can not use an
+ over-provisioning factor greater than 4.
+
+
+
+
+
+ Service Offering Limits and Over-Provisioning
Service offerings limits (e.g. 1 GHz, 1 core) are strictly enforced for core count. For example, a guest with a service offering of one core will have only one core available to it regardless of other activity on the Host.
Service offering limits for gigahertz are enforced only in the presence of contention for CPU resources. For example, suppose that a guest was created with a service offering of 1 GHz on a Host that has 2 GHz cores, and that guest is the only guest running on the Host. The guest will have the full 2 GHz available to it. When multiple guests are attempting to use the CPU a weighting factor is used to schedule CPU resources. The weight is based on the clock speed in the service offering. Guests receive a CPU allocation that is proportionate to the GHz in the service offering. For example, a guest created from a 2 GHz service offering will receive twice the CPU allocation as a guest created from a 1 GHz service offering. &PRODUCT; does not perform memory over-provisioning.
-
+
+
\ No newline at end of file
diff --git a/docs/en-US/working-with-hosts.xml b/docs/en-US/working-with-hosts.xml
index 83cd8b2bdc6..93adcfc2b4a 100644
--- a/docs/en-US/working-with-hosts.xml
+++ b/docs/en-US/working-with-hosts.xml
@@ -35,5 +35,6 @@
+