> For the complete documentation index, see [llms.txt](https://xiayingp.gitbook.io/build_a_os/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xiayingp.gitbook.io/build_a_os/file-system.md).

# File System

- [Overview and Disk Layout](https://xiayingp.gitbook.io/build_a_os/file-system/overview-and-disk-layout.md): 7 layers of file system
- [Buffer Cache](https://xiayingp.gitbook.io/build_a_os/file-system/buffer-cache.md)
- [Design Inode Layer](https://xiayingp.gitbook.io/build_a_os/file-system/design-inode-layer.md)
- [Inode Content](https://xiayingp.gitbook.io/build_a_os/file-system/inode-content.md)
- [Block Allocator](https://xiayingp.gitbook.io/build_a_os/file-system/block-allocator.md)
- [Design a log system for crash recovery](https://xiayingp.gitbook.io/build_a_os/file-system/design-a-log-system-for-crash-recovery.md)
- [Directory Layer](https://xiayingp.gitbook.io/build_a_os/file-system/directory-layer.md)
- [Path names](https://xiayingp.gitbook.io/build_a_os/file-system/path-names.md)
- [File Descriptor Layer](https://xiayingp.gitbook.io/build_a_os/file-system/untitled-2.md)
- [FS System Calls](https://xiayingp.gitbook.io/build_a_os/file-system/untitled.md)
- [XV6 VS Real World](https://xiayingp.gitbook.io/build_a_os/file-system/xv6-vs-real-world.md)
- [Make Xv6 File disk management system](https://xiayingp.gitbook.io/build_a_os/file-system/make-xv6-file-disk-management-system.md)
- [Write FS simulator in python](https://xiayingp.gitbook.io/build_a_os/file-system/write-fs-simulator-in-python.md)
- [How Redirect Shell command works](https://xiayingp.gitbook.io/build_a_os/file-system/how-redirect-shell-command-works.md)


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://xiayingp.gitbook.io/build_a_os/file-system.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
