Page 191 - Cloud computing: From paradigm to operation

Framework and requirements for cloud computing 1

6.4.3 I/O virtualization

I/O virtualization refers to dividing a single physical I/O into multiple isolated logical I/Os. There are two
modes of I/O virtualization: software based and and hardware-assisted I/O virtualization:
– Software based mode simulates I/O devices based on software.
– The hardware-assisted mode provides better performance by reducing a hypervisor's participation
in I/O processing by using hardware.
A network adapter is an I/O device specifically for data transmission. A network adapter provides an isolated
logical I/O based on a single physical I/O to receive and send data packets inside and outside of a physical
machine as virtual network interfaces in order to improve interface utilization.

6.5 Scalability of components in the physical machine

Scalability of components in a physical machine allows enhancing the processing unit, power supply and
cooling components of the physical machine.
6.5.1 Scalability of the processing unit

Scalability of the processing unit allows the processing units of a physical machine to be expanded. Scalability
of the processing unit provides more hardware processing resources in order to meet potential growth
needs, such as providing more CPU and memory resources to host more VMs with the growth of business
needs.
There are several ways to expand processing units as shown hereafter with availability of motherboard
interfaces and enclosure:
– Replacing components of a processing unit with other components with higher capability, such as a
CPU, memory, storage and I/O devices;
– Adding components to a processing unit, such as a CPU, memory, storage and I/O devices;
– Replacing processing units with other processing units with higher capability;
– Adding processing units to the physical machine.

6.5.2 Scalability of power supply
Scalability of power supply allows the power supply of a physical machine to be expanded. Scalability of
power supply provides more power in future for the potential increasing power consumption needs of the
physical machine, such as providing more power for additional processing units.
There are several ways to expand power supply as shown hereafter with availability of enclosure:
– Replacing power supplies of a physical machine with other power supplies with higher capability;
– Adding power supplies to the physical machine.

6.5.3 Scalability of cooling

Scalability of cooling allows the cooling capability of a physical machine to be increased. Scalability of cooling
provides a higher cooling capability to meet the potential increasing cooling needs of the physical machine.

There are several ways to expand cooling capability as shown hereafter with availability of enclosure:
– Replacing cooling components of a physical machine with other cooling components with higher
capability;
– Adding cooling components to the physical machine.

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