Page 193 - Cloud computing: From paradigm to operation

Framework and requirements for cloud computing 1

7.1.1.4 I/O device requirements
– Hardware-assisted I/O virtualization: It is recommended that a physical machine supports
hardware-assisted I/O virtualization to improve the performance of I/O virtualization.
– I/O devices direct accessing: It is recommended that a physical machine supports I/O devices direct
accessing so that a virtual machine can directly access hardware I/O devices.
NOTE 1 – I/O devices direct accessing refers to technologies supporting VM's native accessing of physical I/O devices.
One example of I/O devices direct accessing is I/O devices pass-through. I/O devices pass-through is an I/O device
assigned directly to a VM. The VM can access the I/O devices without a hypervisor's participation.
– Workload offload: It is recommended that a physical machine support offloading workload to I/O
devices to reduce the load of the CPU.
NOTE 2 – In offloading workload, hardware I/O devices execute workload instead of software on a CPU in order to
relieve the CPU's overhead. An example of offloading workload is checking transmission control protocol (TCP)
checksum in a network interface card (NIC) and not in a CPU.
– Hardware acceleration: It is recommended that a physical machine supports application-specific
hardware acceleration to perform specific applications more efficiently.
NOTE 3 – Application-specific hardware is customized for a particular use, rather than intended for general-purpose
use. An example of application-specific hardware is a graphics processing unit (GPU).
7.1.2 Power supply requirements
– Power supply replacement: It is recommended that a physical machine supports substitution with
other power supplies to allow power supply upgrade or replacement of a faulty power supply.
– Supporting power redundancy: It is recommended that a physical machine supports redundant
power supply to keep powered on in case of main power supply failure.
NOTE 1 – N+1 redundancy of power supply is widely used (N: number of power supplies based on total power budget).
– Minimum energy consumption: It is recommended that a physical machine provides minimum
energy consumption.

– Interface for monitoring power: It is recommended that a physical machine supports an interface
to a management component for monitoring status of the power supply.
NOTE 2 – An example of the interface for monitoring power is a power management bus (PMBus).

7.1.3 Cooling requirements
– Cooling component replacement: It is recommended that a physical machine supports substitution
with other cooling components to allow substitution of a faulty cooling component.
– Cooling component redundancy: It is recommended that a physical machine supports cooling
component redundancy to maintain temperature in case of main cooling component failure.
– Interface for controlling fan speed: It is recommended that a physical machine supports an interface
to a management component to control fan speed.
NOTE – An example of an interface for controlling fan speed is a pulse width modulation (PWM) management
component.

7.1.4 Enclosure requirements
– Monitoring status of the physical machine: It is recommended that a physical machine provides a
status panel to check whether components of the physical machine are installed and working
correctly.
– Visual indications: It is recommended that a physical machine provides visual indications of working
state (e.g., starting, running, stopped, faulty), suitable for administrators of the physical machine to
understand.
– Equipment for mounting and removal: It is recommended that a physical machine supports safe
mounting and easy removal of all components in the enclosure.
– Circulation of air flow: It is recommended that a physical machine supports circulation of enough
air flow to minimize the heat generated inside the enclosure with cooling components.

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