Citrix Systems 6 manual Name Default Description

name	default	description
memory-overhead	1048576 (for example)	The memory overhead due to
		virtualization

Dynamic memory values must be within the boundaries set by the static memory values. Additionally the memory target must fall in the range between the dynamic memory values.

Note:

The amount of memory reported in XenCenter on the General tab in the Xen field may exceed the values set using this mechanism. This is because the amount reported includes the memory used by the control domain, the hypervisor itself, and the crash kernel. The amount of memory used by the hypervisor will be larger for hosts with more memory.

To find out how much host memory is actually available to be assigned to VMs, get the value of the memory- free field of the host, and then use the vm-compute-maximum-memorycommand to get the actual amount of free memory that can be allocated to the VM:

xe host-list uuid=<host_uuid> params=memory-free

xe vm-compute-maximum-memory vm=<vm_name> total=<host_memory_free_value>

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