One disk, two jobs
A technician has one big new disk. The system should live in one place, and the user's files in another. Then a bad update can be fixed without touching the files.
The answer is to cut the disk into parts. Each part is called a partition.
Key words
| Word | What it means |
|---|---|
| Partition | a separate section of a drive |
| Partition table | the list on a drive that says where each partition starts and ends |
| MBR | master boot record: an older partition table with a limit of four main entries |
| GPT | GUID partition table: a newer table that allows many partitions and huge drives |
| Primary partition | a main partition that the computer can start from |
| Extended partition | a container that holds logical partitions |
| Logical partition | a partition made inside an extended partition |
| Basic disk | a disk that uses a plain partition table |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can describe basic and dynamic disks, primary, extended and logical partitions, and GPT.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
The older way: MBR
An MBR table has room for only four entries. These are primary partitions. A PC can start from a primary partition.
What if you need more than four? One entry can be an extended partition. It does not hold files itself. It is a container for logical partitions, and you can make many inside it.
Build an MBR image with three partition kinds
truncate -s 64M old.img && parted -s old.img mklabel msdos mkpart primary ext4 1MiB 20MiB mkpart extended 20MiB 100% mkpart logical ext4 21MiB 40MiB mkpart logical ext4 41MiB 60MiB && parted -s old.img printA command for the lesson’s lab terminal. It is shown here and not run.
The newer way: GPT
GPT is the modern table. It allows up to 128 partitions in common use, and drives much bigger than MBR can handle. Every GPT partition is an ordinary partition. There is no primary, extended or logical.
Most new PCs use GPT, with a modern start-up system.
Build a GPT disk image with two partitions
truncate -s 64M disk.img && parted -s disk.img mklabel gpt mkpart boot fat32 1MiB 17MiB mkpart system ext4 17MiB 100% && parted -s disk.img printA command for the lesson’s lab terminal. It is shown here and not run.
MBR and GPT compared
| MBR | GPT | |
|---|---|---|
| Main entries | Four | Up to 128 in common use |
| Needs an extended partition for more? | Yes | No |
| Partition types | Primary, extended, logical | Just partitions |
| Very large drives | Limited to about 2 TB | Supported |
| Age | Older | Newer, now the usual choice |
The cells students fill in are left blank in this preview.