Hardware Management - Deploying and Managing a Cloud Infrastructure - page 227

Though tape storage might have taken a backseat to faster and more easily accessible
disk arrays, it is still being used as a cheap archival storage system. Now, with the continu-
ously increasing demands for high-capacity, low-cost media with a long storage life, tape
storage is gaining wide use in cloud computing systems.
In the age of cloud computing and big data, the challenge is to contribute to the retention
and analysis of immense and diverse data. In the area of analysis, the demand is for signifi-
cantly enhanced I/O performance because of the need for fast processing. Disks and SSDs
can serve well for this purpose. But in the area of retention, there is an incomparably greater
quantity of data that needs to be stored than in the past, and it is important to archive it at
low cost for a very long time. We refer to low cost not only for initial investments but also in
terms of operations management and energy costs. This is where tape storage shines.
Tape media is very cheap for the storage density it provides; it costs less to maintain
because minimal energy is expended while it's idle, so heat is not an issue, which also
helps in its reliability and lifespan.
Solid-State Drives
The solid-state drive (SSD) is a relatively new storage technology, having more in common
with flash drives than disks drives. It is basically a high-capacity flash-based storage device.
Because there are no moving mechanical parts, failure is less likely compared to disks.
However, capacity is not yet where it should be, but it's steadily increasing. SSDs were ini-
tially more expensive compared to disks, but that gap is slowly getting smaller. There will
come a time when SSDs offer more capacity at a lower costs than disk drives.
SSDs are currently the fastest storage media available and are being used in cloud
computing and big data, especially for systems that deal with dynamic data and need to
move it around frequently for analysis and other processes.
Disk
Disk storage is the most common storage media being used in the world today; it provides a
combination of performance, capacity, and affordability. It is getting cheaper to manufacture
large-capacity disks as the technology matures. The problem with it is actually reliability;
there is only so much we can do to make it durable because moving parts will always wear
down and break faster than nonmoving ones. It also requires relatively more energy to run a
single disk than it does to run a SSD or tape drive. A SSD requires only a little power to run,
and although it's also mechanical, a tape drive can simply stop running when it's not in use,
compared to a disk, which continues to spin even when idle. This means that a disk storage
array actually needs sufficient cooling to maintain performance and avoid failure.
Proper Allocation of Hardware Resources (Host)
Cloud computing promises virtually unlimited resources, but this is only due to smart pro-
visioning, scalability, and the ease of simply adding additional hosts and storage arrays to
increase capacity. But the truth is, actual resources are very limited, and that is why they
should be allocated properly.