Where is file information stored?

[chrstrbrts]

Hello,

What I mean is where is file system metadata about files stored?

I'm asking about information like date of file creation, last modified date, user who created it, byte size, etc.

Is this information somehow stored with the file's data or is it kept apart from the file's data in some data structure in the file system's ledger?

Thanks.

 

[AMDisTheBEST]

i think it is handled by the OS

 

[Gryz]

As I've written before, in another one of your questions: it all depends on what file-system you are using. What else do you think a file-system is for ? Different file-systems have been designed to solve different problems. Or optimize for different situations. A file-system on a DVD-ROM has different requirements than a file-system on a HDD. Heck, I bet file-systems on SSDs behave differently from being on a HDD. There are file-systems that try to improve read/search speeds. And there are file-systems that optimize the situation where you write more than you read. Some file-systems were made so that they are more reliable than usual. Etc, etc.
https://en.wikipedia.org/wiki/File_system#Types_of_file_systems

In file-systems that originated from Unix, the meta-data is stored in something called an inode (or i-node).
https://en.wikipedia.org/wiki/Inode

In FAT file-system, the meta-data is in a separate pre-allocated table, called the File Allocation Table.
https://en.wikipedia.org/wiki/File_Allocation_Table#Concepts

Modern file-systems use even more complex algorithms to store stuff.
https://en.wikipedia.org/wiki/Comparison_of_file_systems

 

[Cogman]

Gryz has it right.

Some filesystems inline that data, ig, it is mixed with the data storage (reiserfs). Others will store it all in one location on disk (NTFS). The pros of inlining it is you really don't have to worry about maintaining metadata storage, it happens as a consequence of the rest of the file system maintenance. The con is that it isn't all in one place so getting it can be expensive. The pro of doing a metadata table/file is that you can have all that information in one quick to scan location (memory locality==speed generally) The drawback is you have to manage and maintain metadata space.