Re: [Gnu-arch-users] archive storage format comments on the size

[David Brown]

On Tue, Sep 30, 2003 at 01:30:26AM +0200, Andrea Arcangeli wrote:

> > IIRC, tar pads out its files to end on a 10k boundary, and has internal
> > padding such that even a 1-byte files takes about 1k to store. Hence, I
> > wouldn't quite go as far to say "no waste of space due to the fs" -- as
> > long as you're willing to consider the tar format a filesystem for those
> > purposes.
> 
> I never notice the 1k alignment of files in tar in practice, sounds
> like if they didn't want to store a 64bit for defining the i_size but I
> never looked into the tar sources so I'm just guessing. Ironically some
> fs does a better compacting job than tar. About the 10k boundary, that
> one doesn't matter at all is a >65M file.

The tar header is 512 bytes, unless the name is very long.  The data is
written in units of 512 bytes, so the minimum there is 512.

The 10k boundary padding is before compression.

Dave