Where does it all go?
A school records every lesson on video. Each one is 2 GB. There are 30 lessons a day. In one year, that is more than 10 000 GB.
The head of IT must decide where to keep it. A bigger hard drive? A box in the office? Something in the cloud?
The answer depends on what the data is for.
Key words
| Word | What it means |
|---|---|
| HDD | a hard disk drive: it stores data on spinning metal discs |
| SSD | a solid state drive: it stores data in chips with no moving parts |
| Removable media | storage you can unplug and carry, such as a USB stick |
| NAS | network attached storage: a box of disks that shares files over the network |
| SAN | storage area network: a fast, separate network that gives servers disks as if they were fitted inside |
| Block storage | data kept in equal sized blocks, like a disk |
| Object storage | data kept as whole objects, each with an ID and a label, in one huge pool |
| Metadata | facts about data, such as its name, size and date |
| Network | computers and devices joined together so they can share data |
| Operating system | the main software that runs a computer |
| Virtual machine | a computer made of software that runs inside a real one |
| Database | an organised store of data that programs can search |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can describe seven kinds of storage and choose the right one for a job.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
HDD and SSD
An HDD spins metal discs under a moving arm. It is cheap for each GB, so it suits big stores of data. It is slower and can break if knocked.
An SSD keeps data in chips. It is much faster, silent and tougher. It costs more for each GB.
Many firms use both: SSD for the programs and busy data, HDD for the big, cheap archive.
HDD against SSD
| Feature | HDD | SSD |
|---|---|---|
| How it stores data | Spinning discs | Flash chips |
| Speed | Slower | Much faster |
| Cost for each GB | Lower | Higher |
| Moving parts | Yes, so it can fail if knocked | None |
| Good for | Big archives and backups | Operating systems and busy databases |
The cells students fill in are left blank in this preview.
NAS and SAN
A NAS is a box of disks on your normal network. People open shared folders on it. It is easy to set up and cheap. It is good for office files.
A SAN is a separate, fast network that joins servers to a big pool of disks. The server sees the space as if it were its own disk. It costs more and needs skill. It suits busy servers and databases.
The core lessons show both. Here you choose between them.
Quick check
Have a go
Quick check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.