Re: something magic about the size of a ports tree

On Tue, Oct 3, 2023, 10:24 AM Dag-Erling Smørgrav <des@freebsd.org> wrote:

> Matthias Apitz <guru@unixarea.de> writes:
> > I have on my poudriere build host a ports tree and wanted to move it to
> > the host where the resulting packages are installed:
> >
> > root@jet:/usr/local/poudriere/ports # du -sh ports20230806
> > 397M    ports20230806
> > root@jet:/usr/local/poudriere/ports # tar cf p.tar ports20230806
> > root@jet:/usr/local/poudriere/ports # ls -lh p.tar
> > -rw-r--r--  1 root wheel  672M Oct  3 18:00 p.tar
> >
> > already the size of the tar file is somewhat magic; but if you un-tar it
> > on the other host I will get:
> >
> > [guru@c720-1400094 ~]$ ls -lh p.tar
> > -rw-r--r--  1 guru wheel  672M  3 oct.  18:00 p.tar
> > [guru@c720-1400094 ~]$ tar xf p.tar
> > [guru@c720-1400094 ~]$ du -sh ports20230806
> > 1,2G  ports20230806
> >
> > How this is possible?
>
> Most files in the ports tree are very small.  On disk, each file gets
> rounded up to the nearest multiple of the filesystem block size, which
> could be as small as 512 bytes or as large as 8 kB (or even more in
> pathological cases).  In a tarball, they get rounded up to the nearest
> multiple of 512 bytes plus an additional 512 bytes per file for
> metadata.
>
> For instance, your average distinfo file (of which there are 30k in the
> ports tree) is only 200-250 bytes long, but it occupies 512 bytes on an
> FFS filesystem, 1 kB in a tarball, and 4 kB on a typical ZFS filesystem.
>
> Note that if the target system is FreeBSD 14 or newer, you can simply
> mount the tarball (`sudo mount -rt tarfs p.tar /usr/ports`).
>

Do we support any compression on top of that? Has support for poudriere
been added for it?

Aldo I want a pony.... I'm mostly curious... I have no immediate plans here
(though aligning with the boot loader and supporting this on a block device
to support rootfs would be cool). Maybe some or all of these wishes would
make good GSOC projects?

Warner

DES
> --
> Dag-Erling Smørgrav - des@FreeBSD.org
>
>