1. Storage Building Blocks
Outcome
Section titled “Outcome”Differentiate access models and trace an application request through the logical layers that turn physical capacity into usable storage.
Level: Foundation · Time: 35 minutes · Prerequisite: none
| Layer | Provides | Does not automatically provide |
|---|---|---|
| Block storage | addressable fixed-size blocks exposed as a device/LUN | files, directories or shared-file coordination |
| File storage | named files and directories through a filesystem protocol | raw block control to the client |
| Object storage | key/object access with metadata through an API | POSIX block or file semantics by default |
application → file/database → filesystem or volume manager → block device/LUN → host path → fabric/network → controller → pool/RAID → mediaA LUN is an addressable block-storage presentation. A host may place a partition table, volume manager, filesystem, database or hypervisor datastore above it. These terms are layers, not interchangeable synonyms.
Practice
Section titled “Practice”Open the Universal RAID Planner and create an eight-disk layout. Record raw capacity, usable capacity, protection overhead and tolerated failures. Explain where that usable capacity could appear in the path above.
Check your understanding
Section titled “Check your understanding”- Why can two filesystems not safely mount the same ordinary block device for independent writes?
- Which layer gives an application directories and filenames?
- Why is a LUN not the same thing as a physical disk?
Production boundary
Section titled “Production boundary”Real arrays may virtualize pools, extents, compression and thin allocation. Product terminology varies; confirm the vendor’s exact object hierarchy before operating it.
Next step
Section titled “Next step”Continue to Performance Fundamentals and use the glossary whenever a term is unfamiliar.