Hardware Management - Deploying and Managing a Cloud Infrastructure - page 243

If hyperthreading is enabled, this doubles the number of logical CPUs in the host for a total
of 32 logical CPUs, so in turn it can support virtual machines with 32 single core vCPUs.
NICs Quantity, Speeds, and Configurations The network must be free for network-
intensive applications and workflows, so if a virtual machine with this type of workflow
has to share the host's NIC with other VMs, the performance of the virtual machine would
be severely impacted. A one-to-one ratio of VMs and NICs should be considered for such
situations.
Internal Hardware Compatibility All the hardware in a cloud data center must be com-
patible. It's true that incompatibility still exists because of programming and manufactur-
ing processes, even if it is not intentional. Therefore, research must be done to ensure that
the different hardware modules to be used are 100 percent compatible without issues and
bugs that may impact performance and availability later.
Storage Media We are actively using three types of storage media. Tape is the cheapest,
with the largest capacity but weakest performance. Disk provides a mixture of both per-
formance and capacity, while SSDs are the best performers, but with the least amount of
capacity and also the most expensive.
Proper Allocation of Hardware Resources (Host) For a host, resource allocation is all
about fancy algorithms for allocation and reclamation of resources. We have to make sure
that idle resources are put to good use and that they are immediately returned when they
are needed by the idle VMs who previously possessed them. We also have to make sure
that metering and dynamic resource allocation is satisfactory.
Proper Virtual Resource Allocation (Tenant/Client) Client allocation of resources is
geared toward satisfactory performance of virtual machines. Resource allocation must be
lean to minimize costs.
Management Differences between Public, Private, and Hybrid Clouds Managing a public
cloud is a serious affair, and proper management of resources is important in serving all
tenants and meeting all service-level agreements. For tenants of a public cloud, lean man-
agement of resources would be the most efficient approach. In a private cloud, management
can be more relaxed; limits for resource use and allocation can be more lax and users can
be allowed to provision as much as they want because resources are plenty. However, this
does not mean that cleanup and reclamation of resources are not required.
Tiering Different tiers provide businesses with different ways to approach their backup
storage needs, which depend on workflow and type of backups. For example, you can
use tape storage for data that belong to the tier 3 category because it is only required as
long-term backups. High-performance storage such as SSD must be used for critical and
dynamic data that changes rapidly, which is considered tier 0 data.
RAID Levels With the RAID method of storage, data is striped in multiple identical disks.
When one or two disks fail, the data is not actually lost because it is still available in other
drives. Each RAID level also features some unique features used for security and recovery.
RAID can be expensive because multiple disks must be used and will contain more or less
the same data.