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 Post subject: ext file system structure vs metadata
PostPosted: Tue Feb 20, 2018 1:21 pm 
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one of the disk benchmark tools I am working on keep saying file metadata overhead because it uses file system calls instead of disk block calls. I am assuming this is referring to generic ext2 file structure, looking at:
https://wiki.osdev.org/File_Systems

or more precisely, metadata appears to stay within he inode (create/modify time etc.) whereas metadata is not referring to complete file system overhead.
Meaning the overhead associated with inode block manipulation, calculation due to various file operation i.e. mount, write, read does not count toward the overhead associated with metadata itself.

inodes
inodes (information nodes) are a crucial design element in most Unix file systems: Each file is made of data blocks (the sectors that contains your raw data bits), index blocks (containing pointers to data blocks so that you know which sector is the nth in the sequence), and one inode block.

The inode is the root of the index blocks, and can also be the sole index block if the file is small enough. Moreover, as Unix file systems support hard links (the same file may appear several times in the directory tree), inodes are a natural place to store Metadata such as file size, owner, creation/access/modification times, locks, etc.

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 Post subject: Re: ext file system structure vs metadata
PostPosted: Thu Mar 01, 2018 9:06 am 
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Location: Athens, Greece
Hi,


I don't know if this document covers it, but have you looked at the inode definition of the ext2 documentation?

Note that I'm not exactly clear about what are you asking for. Could you elaborate?


Regards,
glauxosdever


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