Storage

ITEC 101: Introduction to Information Technology

Mr. Seng Theara

Learning Outcome

 

  • Identify different types of storage devices and technologies, including HDDs, SSDs, optical discs, flash drives, and cloud storage.
  • Explain the key characteristics of storage systems, including capacity, speed, volatility, and random versus sequential access.
  • Compare HDDs and SSDs in terms of performance, cost, capacity, and reliability.
  • Describe how partitions, file systems, and RAID are used to organize, manage, and protect stored data.
  • Evaluate the benefits and limitations of local, network, and cloud storage.
  • Recommend appropriate storage solutions for different users based on their storage requirements, budget, performance needs, and data protection.

Storage System

Your laptop suddenly stops working!

Imagine that you have spent two weeks preparing your final project. You saved everything on your laptop.Tomorrow is the submission deadline, but tonight your laptop stops working.

Your laptop suddenly stops working!

Imagine that you have spent two weeks preparing your final project. You saved everything on your laptop.Tomorrow is the submission deadline, but tonight your laptop stops working.

  • Are your files lost forever?

  • Where were your files stored?

  • What could you have done to prevent losing your work?

Storage Fundamental

Storage Fundamental

Where does your computer keep its data?

Storage Fundamental

Where does your computer keep its data?

RAM

SSD/HDD

Storage Fundamental

Where does your computer keep its data?

RAM

SSD/HDD

  • Temporary working memory
  • Volatile
  • Used by running programs
  • Contents normally lost without power
  • Keeps data long-term
  • Nonvolatile

  • Stores OS, apps, and files

  • Data remains without power

If I upgrade my laptop from 8 GB to 16 GB RAM, will I have more space to save photos?

If I upgrade my laptop from 8 GB to 16 GB RAM, will I have more space to save photos?

No. More RAM can help with running programs, but it does not increase permanent storage capacity.

Storage Device vs. Storage Media

Storage Device vs. Storage Media

  • Storage medium: The physical material where data is recorded.

  • Storage device: The hardware used to access or manage the storage medium.

Storage Devices vs. Storage Media

  • Storage medium: The physical material where data is recorded.

  • Storage device: The hardware used to access or manage the storage medium.

Medium

Device

  • DVD Disc
  • SD Card
  • Magnetic Tape
  • DVD Drive
  • SD Card Reader
  • Tape Drive

Storage Devices vs. Storage Media

Medium

Device

Classify the Storage

Classify each as Volatile, Nonvolatile or Remote Storage

RAM                      
Internal SSD                       
USB flash drive                       
External HDD                        
Google Drive                       
SD card                        

Classify the Storage

Classify each as Volatile, Nonvolatile or Remote Storage

RAM                      Volatile memory
Internal SSD                       Nonvolatile local storage
USB flash drive                       Nonvolatile local storage
External HDD                        Nonvolatile local storage
Google Drive                        Remote/cloud storage
SD card                        Nonvolatile local storage

HDD vs. SSD

HDD

SSD

HDD vs. SSD

HDD

SSD

Spinning magnetic platters and moving read/write heads

Flash memory chips, no moving parts

HDD vs. SSD

HDD

SSD

 

Magnetic technology

Flash memory

Moving mechanical parts

No moving parts

Generally slower access

Generally faster access

Usually cheaper per GB

Usually more expensive per GB

More vulnerable to shocks during operation

More resistant to mechanical shocks

HDD vs. SSD

True or False: SSDs never fail because they have no moving parts.

HDD vs. SSD

True or False: SSDs never fail because they have no moving parts.

False. SSDs can fail because of controller problems, electronic faults, firmware issues

Partitions and File Systems

 Your computer has one physical SSD, but Windows displays C: and D:. How is that possible?

Partitions and File Systems

A student has a 64 GB USB drive formatted as FAT32.

They want to copy a single 6 GB video file. The USB drive has enough free space, but Windows reports that the file is too large for the destination file system.

  • Why does the error occur?

  • Is the USB drive broken?

  • What could solve the problem?

Partitions and File Systems

A student has a 64 GB USB drive formatted as FAT32.

They want to copy a single 6 GB video file. The USB drive has enough free space, but Windows reports that the file is too large for the destination file system.

FAT32 has a maximum individual file size of approximately 4 GB. A compatible file system such as exFAT can support larger files.

Partitions and File Systems

A student has a 64 GB USB drive formatted as FAT32.

They want to copy a single 6 GB video file. The USB drive has enough free space, but Windows reports that the file is too large for the destination file system.

FAT32 has a maximum individual file size of approximately 4 GB. A compatible file system such as exFAT can support larger files.

  • NTFS  - widely used for Windows system drives

  • FAT32 - broadly compatible, but has a 4 GiB maximum individual file size

  • exFAT  - often used for removable storage and large files

Optical discs and flash storage

Optical Discs

Flash Storage

Optical discs and flash storage

Optical Discs

Flash Storage

 CD, DVD, Blu-ray

USB flash drives

     Storage type                                                            Typical capacity

CD

                                             700 MB

Single-layer DVD

                                              4.7 GB

Single-layer Blu-ray

                                              25 GB

USB flash drive

                                               Varies widely

Why are some optical disc read-only?

Why are some optical disc read-only?

  • ROM: Read-only

  • R: Recordable once

  • RW / RE: Rewritable

Why are some optical disc read-only?

ROM - Read-Only

A pre-recorded software installation DVD or movie disc.

You can read the data, but you cannot change or delete its contents.

Why are some optical disc read-only?

ROM - Read-Only

A pre-recorded software installation DVD or movie disc.

You can read the data, but you cannot change or delete its contents.

R - Recordable

You can record your photos, music, or documents onto the disc. Once an area is recorded, it cannot be erased and rewritten.

Some discs support adding more files in later sessions if space remains and the disc hasn't been finalized.

Why are some optical disc read-only?

ROM - Read-Only

A pre-recorded software installation DVD or movie disc.

You can read the data, but you cannot change or delete its contents.

R - Recordable

You can record your photos, music, or documents onto the disc. Once an area is recorded, it cannot be erased and rewritten.

Some discs support adding more files in later sessions if space remains and the disc hasn't been finalized.

Example: CD-RW, DVD-RW, or BD-RE (Blu-ray).

You can record data, erase it, and record new data repeatedly, subject to the disc's rewrite endurance.

RW / RE - Rewritable

How do storage device find your data?

How do storage device find your data?

1. Random Access (Direct Access)

Random access allows a computer to retrieve data from a particular location without reading all the preceding data.

For example, imagine you have 100 photos stored on an SSD. You want to open photo number 85.With random access, the computer can directly locate and retrieve photo 85 without first reading photos 1–84.

How do storage device find your data?

1. Random Access (Direct Access)

Random access allows a computer to retrieve data from a particular location without reading all the preceding data.

For example, imagine you have 100 photos stored on an SSD. You want to open photo number 85.With random access, the computer can directly locate and retrieve photo 85 without first reading photos 1–84.

  • SSD, HDD, USB flash driveSD , DVD, and Blu-ray discs

How do storage device find your data?

2. Sequential Access

Sequential access retrieves data in order. To reach a particular location, the storage medium must move through the preceding positions.

For example, imagine your data is stored on a magnetic tape.

If the data you want is near the end of the tape, the drive must wind the tape forward until it reaches the correct location.

How do storage device find your data?

2. Sequential Access

  • Magnetic tape drives (LTO tape)

  • Older cassette-based data storage systems

Where does your file go when you upload it to Google Drive?

Where does your file go when you upload it to Google Drive?

Your PC

Other Device

Internet

Internet

When you upload a file to Google Drive, it is transferred through the Internet and stored on physical storage devices in Google's data centers.

Data Center

Example of Cloud Storage Sevice

 

Example of Cloud Storage Sevice

 

Cloud Storage: Benefits vs. Limitations

Cloud Storage: Benefits vs. Limitations

                    Benefits                                                                     Limitations

Access files anytime, anywhere

Internet connection usually required

Easy file sharing and collaboration

Slow uploads/downloads with poor Internet

Synchronizes files across devices

Accidental deletions may synchronize

Helps recover files if a device fails

Not a complete backup solution

No need to buy physical storage hardware.

Limited free storage; subscription costs

Easy to increase storage capacity

Ongoing costs for larger storage

Provider maintains storage infrastructure

Privacy and security concerns

Access files from multiple devices

Service outages may restrict access

NAS

NAS

Network Attaced Storage

NAS

NAS (Network Attached Storage) is a storage system accessible over a network.

Example: A small office uses a NAS so several computers can access shared files.

 NAS is a storage-sharing solution, not automatically a backup.

NAS Explain

RAID

  • RAID 0 (Striping): Uses multiple drives together to improve performance and combine capacity.

  • RAID 1 (Mirroring): Stores identical data on two drives to protect against a single drive failure.

RAID Explain