Digital Storage and Backup – JSS3 Digital Technologies Lesson Note (Second Term)

A backup is a second copy of your important files, kept in a different place from the original.

Behavioural objectives

By the end of the lesson, students should be able to:

1. Define digital storage and backup.
2. State four reasons for backing up files.
3. Name examples of physical backup devices and cloud storage services.
4. Compare physical backups with cloud backups.
5. Explain and apply the 3-2-1 backup rule.

What is digital storage?

Digital storage is the keeping of files and data on a device or online so that they can be used later.

• Internal storage: the hard drive (HDD) or solid state drive (SSD) built into a computer, or the memory built into a phone.
• External storage: a device you plug in, such as a flash drive or external hard drive.
• Online storage: space on a company’s computers that you reach through the internet, called the cloud.

Units of storage

• Byte: the basic unit, enough to hold one character.
• Kilobyte (KB), Megabyte (MB), Gigabyte (GB), Terabyte (TB): each unit is larger than the one before it.
• Example: a text assignment may need KB or MB, while many photos and videos need GB.

What is a backup?

A backup is a second copy of your important files (photos, assignments, music) stored in a different place from the original.

• Example: a copy of your project on a flash drive, as well as the one on your phone.
• Comparison: imagine a story written in your notebook that a goat eats or the rain ruins. With no second copy, the work is gone.

Why do we need to back up files?

We back up files to avoid losing important work when something goes wrong with the device that holds it.

1. Hardware failure: hard drives (HDDs) have moving parts that can wear out and break.
2. Theft or loss: if your phone is stolen, your memories are not stolen with it.
3. Accidents: a drink spilled on a laptop can damage its memory instantly.
4. Viruses: ransomware is harmful software that locks your files and demands money to release them.
5. Accidental deletion: a file deleted by mistake can be restored from a backup.

The Golden Rule: if you have only one copy of a file, you do not really own it. You are borrowing it until something goes wrong.

What are the types of backup?

There are two main types of backup: physical backups on external devices and cloud backups on the internet.

What is a physical backup?

A physical backup is a copy of your files on an external storage device that you plug into your computer, then unplug and keep safe.

• USB flash drive: small, cheap and easy to carry, so it is good for school projects.
• External hard drive (HDD or SSD): looks like a small book and can store thousands of movies or every photo you have taken.
• Memory card (SD card): usually found inside a camera or phone.

Pros and cons of physical backups

• Pro: you do not need the internet to get your files back.
• Pro: you pay once for the device and own it.
• Con: if you lose the drive or it gets crushed, your backup is gone too.
• Con: you must remember to plug it in and copy new files.

What is cloud storage?

Cloud storage is a service that keeps your files on a company’s powerful computers (servers) in a safe building elsewhere in the world, and lets you reach them over the internet.

• Google Drive: used by many for school documents.
• iCloud: used by iPhone users to save photos.
• OneDrive: Microsoft’s service, built into Windows.
• Dropbox: a simple “box in the sky” for all types of files.

Pros and cons of cloud storage

• Pro: you can reach your files from anywhere. If you lose your phone in Lagos, you can log in on a computer in Abuja and your photos are still there.
• Pro: a lost or damaged device does not destroy the copy.
• Con: you need the internet to upload and download files.
• Con: free space is limited (Google gives about 15GB free), and you pay for more.
• Con: anyone who learns your password can reach your files, so keep it secret.

How do physical and cloud backups compare?

What is the 3-2-1 backup rule?

The 3-2-1 rule is a simple plan that technicians use to make sure important files are never lost.

1. 3 copies: keep three copies of any important file (the original plus 2 backups).
2. 2 different media: use two different types of storage, for example your computer’s hard drive and a USB flash drive.
3. 1 off-site: keep at least one copy in a different physical place, for example in the cloud.

How do you back up your files?

Backing up to a flash drive or external drive

1. Plug the device into the USB port.
2. Open the folder that holds your files.
3. Select the files and choose Copy.
4. Open the external drive and choose Paste.
5. Wait until copying finishes, then safely eject the drive.
6. Keep the drive in a safe place.

Backing up to the cloud

1. Sign in to your account (for example Google or iCloud).
2. Choose Upload, or turn on automatic backup in settings.
3. Select the files or folders.
4. Wait for the upload to finish and check that the files appear online.

Class discussion and activity

• Question: if you have 500 family photos on your phone, what is the best way to back them up today?
• Task: look at the Google Photos or iCloud settings on a phone to see whether Auto-Backup is turned on. This is a “set it and forget it” way to stay safe.

Teacher’s note: remind students that cloud storage usually gives a little free space (for example 15GB on Google), and you pay if you want more.

Evaluation

1. Define a backup.
2. State four reasons why files should be backed up.
3. Name three physical backup devices and three cloud services.
4. Give one advantage and one disadvantage of cloud storage.
5. Explain what each number in the 3-2-1 rule means.

Assignment

Choose five important files you own (for example assignments or photos). Write a backup plan for them that follows the 3-2-1 rule. Name the device or service you would use for each copy.