Qualification:
Cambridge Advanced Nationals in Computing (AAQ)
Certificate:
Computing: Application Development (H029 / H129)
Unit:
F161: Developing Application Software
1.3 - Storage
There are five types of on-site (local) storage you need to know - file servers, network attached storage (NAS) devices, portable storage devices, solid state drives (SSD) and storage area networks (SAN).
In regards to cloud storage, you need to know the different locations (private, public, hybrid and community) and types (file, object, block, elastic/scalable and cloud-based database services.
You need to be aware of the characteristics, advantages and disadvantages of each storage location and type as well as the factors to consider when selecting a storage location and type.
What You Need to Know
On-Site Storage
On-site storage is physically located at the same site as the user or organisation, such as in a building or office, rather than being stored over the internet in the cloud. It gives the organisation direct control over its storage devices and data.
File Servers
File servers are central computers that store files for users on a network, allowing multiple people to access and share data from one location.
They make it easy to manage files, set user permissions and perform backups in one place.
However, they can be expensive to set up and maintain, and if the server fails, all users may lose access. Performance can also slow down if too many users access it at once.
NAS Devices
A network attached storage (NAS) device is a dedicated storage unit connected to a network, designed specifically for storing and sharing files.
It is usually simpler and cheaper than a full file server, making it suitable for small networks or home use as they are easy to install and useful for backups.
But they are less powerful, have limited scalability and their performance depends heavily on the network speed.
Portable Storage Devices
Solid States Drives (SSDs)
Portable storage devices, such as USB flash drives and external hard drives, are small, removable devices that connect directly to a computer.
They are highly portable, affordable and convenient because they do not require a network connection.
However, they are easy to lose or damage, can pose security risks if stolen or infected with malware, and typically have less storage capacity than larger systems.
SSDs are storage devices that use flash memory instead of moving parts and are commonly found inside computers or used externally.
They offer very fast read and write speeds, are durable, silent and energy efficient.
On the downside, they are more expensive than traditional hard drives, often have lower storage capacity for the price, and can wear out over time due to a limited number of write cycles.
Storage Area Networks
A storage area network (SAN) is a high-speed network that provides access to consolidated storage, typically used by large organisations.
It allows for extremely fast data access, high reliability and can be scaled to store very large amounts of data.
However, SANs are very expensive to implement, complex to manage and require specialist knowledge to maintain.
Cloud Storage Locations
Cloud storage is a way of storing data on servers that are accessed over the internet, allowing users to access their files from anywhere with an internet connection.
Private Cloud
Public Cloud
A private cloud is used by a single organisation, either hosted on-site or by a third party.
It offers high levels of control, security and customisation, making it suitable for organisations handling sensitive data or needing to comply with data privacy regulations.
However, it is expensive to set up and maintain and the organisation is responsible for managing and updating the system.
A public cloud is provided by external companies and shared between multiple users or organisations over the internet. Examples include Google Drive and Dropbox.
It is cost-effective, easy to access from anywhere and requires no maintenance by the user. It is also scalable if more space is required at a later time and convenient.
However, it offers less control over data, may raise security and privacy concerns and depends on a reliable internet connection.
Hybrid Cloud
A hybrid cloud combines both private and public cloud storage, allowing data to be shared between them. Organisations can keep sensitive data in the private cloud while using the public cloud for less critical data.
This provides flexibility, cost efficiency and better security control.
However, it can be complex to set up and manage and integrating the two systems can be challenging.
Community Cloud
A community cloud is shared by several organisations with similar needs, such as schools or government departments.
The advantages include cost sharing, tailored security and easier collaboration between organisations.
However, it may be less flexible than other cloud types and there can be concerns about data privacy and management between different organisations.
Cloud Storage Types
Cloud storage types are the different ways data can be organised, stored and accessed in the cloud, with each type designed for different uses and performance needs.
File Storage
File storage organises data in a hierarchical structure of folders and files, similar to how files are stored on a personal computer.
It is easy to understand and use, making it ideal for shared drives and everyday file access due to its compatibility with many systems.
However, it can become slow or inefficient with very large amounts of data and scaling up can be more difficult compared to other cloud storage types.
Object Storage
Object storage stores data as individual objects, each with metadata and a unique identifier, rather than in folders. It is designed for large amounts of unstructured data such as images, videos and backups.
Its advantages include excellent scalability, high durability and cost-effectiveness for large datasets.
However, it is not suitable for applications that require fast, frequent updates and it can be harder to work with compared to traditional file systems.
Block Storage
Elastic / Scalable Storage
Block storage splits data into fixed-size blocks and stores them separately.
It provides very fast access and high performance, making it suitable for systems that need quick read/write operations. The advantages are speed, reliability and flexibility.
However, it is more complex to manage, can be expensive, and does not include built-in file organisation like file storage.
Elastic storage automatically increases or decreases capacity based on demand. It is commonly used in cloud environments where storage needs change frequently.
The main benefits are flexibility, cost efficiency (only pay for what you use) and no need to predict storage requirements in advance.
However, costs can become unpredictable and it relies heavily on a stable internet connection and provider availability.
Cloud-Based Database Services
These are cloud services designed specifically to store and manage structured data using databases. They handle tasks such as backups, updates and scaling automatically.
The advantages include ease of use, automatic maintenance, scalability and high availability.
However, they can be costly over time, offer less control than self-managed databases and may raise concerns about data security and vendor lock-in.
Questo's Questions
1.3 - Storage:
1. Choose the most storage type and explain your answer. [4 each]
a. A school wants a central place where all teachers can save and share files.
b. A photographer needs to carry thousands of photos between clients.
c. A bank needs extremely fast storage for critical systems.
d. A company wants storage that automatically grows as it stores more data.
e. A video streaming company needs to store millions of videos.
2. For each scenario, recommend a storage location and explain why. [4 each]
a. A hospital storing confidential patient records.
b. A small business with a limited budget.
c. A university working with several partner colleges.
d. A company that wants to keep sensitive data private but also use cheaper cloud storage.
3. Give two advantages and two disadvantages for each cloud storage type (file storage, object storage, block storage, elastic / scalable storage, cloud-based database services. [1]
Every photo, video or file you upload to the cloud is often copied to multiple servers in different locations (this is called redundancy). So if one server fails, your data can still be recovered.
Did You Know?
