RAID Simulator

This project is a RAID simulator that demonstrates various RAID configurations including RAID 0, RAID 1, RAID 5, and RAID 10. It features a server-client architecture that allows users to interact with the RAID systems, simulate crashes, and manage backups.

Project Structure

raid-simulator
├── client
│   ├── public
│   │   └── index.html
│   ├── src
│   │   ├── components
│   │   │   ├── RaidController.tsx
│   │   │   └── RaidVisualizer.tsx
│   │   ├── services
│   │   │   └── api.ts
│   │   ├── App.tsx
│   │   └── index.tsx
│   ├── package.json
│   └── tsconfig.json
├── server
│   ├── src
│   │   ├── controllers
│   │   │   └── raidController.ts
│   │   ├── models
│   │   │   ├── Disk.ts
│   │   │   └── Raid.ts
│   │   ├── routes
│   │   │   └── raidRoutes.ts
│   │   ├── services
│   │   │   └── raidService.ts
│   │   └── server.ts
│   ├── package.json
│   └── tsconfig.json
└── README.md

Features

• RAID Configurations: Supports RAID 0, RAID 1, RAID 5, and RAID 10.
• Crash Simulation: Users can simulate disk failures and observe how the RAID system responds.
• Disk Replacement/Rebuild: Replace failed disks and observe rebuild behavior (RAID 1/5/10).
• Disk Data Viewer: Read a slice of a specific disk for learning/debugging.

Getting Started

Prerequisites

• Node.js
• npm or yarn

Installation

1. Clone the repository:

   git clone <repository-url>
   cd raid-simulator
   

2. Install server dependencies:

   cd server
   npm install
   

3. Install client dependencies:

   cd client
   npm install
   

Running the Application

1. Start the server:

   cd server
   npm start
   

2. Start the client:

   cd client
   npm start
   

3. Open your browser and navigate to http://localhost:3000 to access the simulator.

Usage

1. Create an array

   • Choose a RAID level and disk count, then click Create RAID.
   • Rules enforced by the simulator:
     • RAID 0: minimum 1 disk
     • RAID 1: minimum 2 disks
     • RAID 5: minimum 3 disks
     • RAID 10: minimum 4 disks and an even number of disks

2. Write data

   • Paste a string into the Write Data input and click Write.

3. Simulate failures and recovery

   • Use Simulate Crash to fail a disk by index.
   • Use Replace Disk to replace a failed disk.
   • Expected behavior:
     • RAID 0: any single disk failure = data loss
     • RAID 1: can tolerate disk failures as long as one disk remains healthy
     • RAID 5: can tolerate exactly one disk failure; two failures = data loss
     • RAID 10: can tolerate one disk failure per mirrored pair; losing both disks in a pair = data loss

4. Read a specific disk

   • Click Read Data on a disk card.
   • This reads a slice of the disk and is meant for learning/debugging.

Testing Data (Copy/Paste)

The simulator uses a 16KB chunk size for striping/parity in RAID 0/5/10. This matters a lot for what you see when reading individual disks.

Quick copy/paste strings

• Tiny (fits in one chunk):

  The quick brown fox jumps over the lazy dog.
  

• Multi-chunk (good general test):

  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-=
  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-=
  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-=
  ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_+-=
  

Exact-size payloads (best for edge cases)

If you want truly deterministic RAID10/RAID5 distribution tests, generate exact byte sizes and send them via the API.

PowerShell examples (Windows):

1. Create a RAID 10 with 8 disks:

$base = 'http://localhost:5000/api/raid'
$create = Invoke-RestMethod -Method Post -Uri "$base/raid/create" -ContentType 'application/json' -Body (@{ raidLevel='RAID10'; numberOfDisks=8 } | ConvertTo-Json)
$raidId = $create.raidId
$raidId

2. Write exactly 64KB (this should touch all 4 mirrored pairs at least once):

$data = 'A' * (64 * 1024)
Invoke-RestMethod -Method Post -Uri "$base/raid/write" -ContentType 'application/json' -Body (@{ raidId=$raidId; data=$data } | ConvertTo-Json)

3. Read 64KB starting at offset 0 from disk 0..7 (useful to see striping offsets):

0..7 | ForEach-Object {
  $i = $_
  $r = Invoke-RestMethod -Method Get -Uri "$base/raid/read-disk/$raidId/$i?offset=0&length=65536"
  "disk $i => length=$($r.data.Length)"
}

Notes:

• If a disk looks “empty”, try reading a later offset like offset=16384 (16KB) or offset=32768 (32KB).
• The disk-read endpoint strips \x00 bytes for display, so binary-looking regions may appear shorter.

API Notes

Base URL: http://localhost:5000/api/raid

• POST /create body: { raidLevel, numberOfDisks }
• POST /write body: { raidId, data }
• POST /simulate-crash body: { raidId, diskIndex }
• POST /replace-disk body: { raidId, diskIndex }
• GET /read-disk/:raidId/:diskIndex?offset=...&length=...

Contributing

Contributions are welcome! Please open an issue or submit a pull request for any enhancements or bug fixes.

License

This project is licensed under the MIT License. See the LICENSE file for details.