linux 往文件写4k大小,[svc]为何linux ext4文件系统目录默认大小是4k?

linux ext4普通盘为什么目录大小是4k?

Why does every directory have a size 4096 bytes (4 K)?

To understand this, you'd better have some basic knowledge of the following (file system):

inode (contains file attributes, metadata of file, pointer structure)

file (can be considered a table with 2 columns, filename and its inode, inode points to the raw data blocks on the block device)

directory (just a special file, container for other filenames. It contains an array of filenames and inode numbers for each filename. Also it describes the relationship between parent and children.)

symbolic link VS hard link

dentry (directory entries)

...

On typical ext4 file system (I reckon most likely this is what you are using), the default inode size is 256 bytes, block size is 4096 bytes.

A directory is just a special file which contains an array of filenames and inode numbers. When the directory was created, the file system allocated 1 inode to the directory with a "filename" (dir name in fact). The inode points to a single data block (minimum overhead), which is 4096 bytes. That's why you see 4096 / 4.0K when using ls.

要理解这个,你首先要懂:(注: 这里我用c7.4,默认xfs:/etc/fstab,我又挂了一个格式化成ext4做的实验)

inode:

file