Re: different compression types for NetBSD-daily/netbsd-11/latest/ sets

[Steve Rikli <sr%genyosha.net@localhost>]

On Thu, Oct 02, 2025 at 01:08:55PM +0700, Robert Elz wrote:
>     From:        Steve Rikli <sr%genyosha.net@localhost>
>   | First question: is the difference intentional? E.g. is there some reason
>   | tgz (tar.gz) is preferred over tar.xz for certain architectures?
> 
> Yes, the only difference (obviously) is which compression method is
> used - xz makes smaller files than gzip (gz) but is much slower to
> compress, and more importantly, uses lots more memory to decompress.
> 
> So, using xz means smaller set sizes (faster network transfer times)
> but requires the system installing them to have sufficient memory to
> achieve that (if relying upon paging, unpacking might take forever).

Ok, I imagined it would be something like that.

So the theory is presumably that these older system types:

> >   tgz : alpha i386 macppc sgimips sparc sparc64

have smaller CPU and RAM than these generally more modern system types:

> >   tar.xz : amd64 evbarm-aarch64

so the older models use the less-resources-to-unpack compression method;
is that about right?

Assuming that's the deal, and further assuming no changes in the daily
sets compression methods status quo, a PR for sysupgrade seems prudent:

- remove sparc64 from the "tar.xz" if-then-else code
- add evbarm-aarch64 to it instead

This would remove the need to change ARCHIVE_EXTENSION in the default
sysupgrade.conf for both system types.  Does that sound correct?

Cheers,
sr.