Unix File System
[INode](https://texonom.com/inode-f59013f016cf41e0a58611a3e72eb5ef) 


### Unix 계열은 모든 것이 파일 (device, directory 등등)
completely all byte and it has meta is main + Ext2 file system
### EXt2
- first block is boot block (boot sector)
- the remainder of the partition is split into block groups
partition → formatting → make file system

![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2F65f58d6d-7321-483b-9b7e-7a9ac69d228e%2Ftemp.jpg?table=block&id=eb67826d-6b83-445c-8f7b-337f5b33b5a9&cache=v2)


### meta data (in right table)
in i-node data structure

> i-node : metadata + index
> index is 128 byte fixed in linux

index data structure is important
![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2F4a4216db-804a-4cea-a39f-83392a55ab5c%2Ftemp.jpg?table=block&id=b925801e-5a81-4f65-8d5c-1d1f367a9080&cache=v2)
![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2F030b7aea-df82-4981-a2db-441197f4323b%2Ftemp.jpg?table=block&id=748e15d5-c5fe-4a15-bc42-d4147ccf0acb&cache=v2)
block address scheme
![](https://www.notion.so/image/https%3A%2F%2Fs3-us-west-2.amazonaws.com%2Fsecure.notion-static.com%2F0e0f4de0-914a-4073-8e55-4b43c65f8e8d%2Ftemp.jpg?table=block&id=b656c03f-0c9c-4410-8132-80596a432efd&cache=v2)
direct blocks is right image
block is 10 so can 10k
if more than 10 then double or triple indirect
which means treating data block as index block
this is because file incoding limit file size
10 + 256 + 256 ^ 2  + ..





