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Systems engineering · Mini File System

Follow a file onto disk.

Write a short message, see where it lands, and recover it after remounting the disk.

Disk LabC driver running in WebAssembly

Try it yourself

  1. 1Write
  2. 2Reopen
  3. 3Seek
  4. 4Read
  5. 5Remount

Step 1 of 5

Write a message

The driver opens a file, breaks the message into blocks, and records their locations.

Printable ASCII characters16 / 50 bytes
Disk map

Virtual partition

Disk map

Starting

Starting the C driver…

Driver trace

Driver operations appear here as you work.

What we built

A C file system that turns file operations into reads and writes on a virtual disk. The file allocation table tracks which blocks belong to each file, and the open file descriptor records where the next read begins.

The browser runs the same driver through WebAssembly. This disk stays in this tab until you reset or reload it.

Read the C source