Re: Switching release media dist sets to .tzst (tar + zstd)?

On Fri, Dec 13, 2024 at 2:16 PM Ed Maste <emaste@freebsd.org> wrote:
>
> I have been reviewing parts of the release artifact build process,
> including ISO and memstick images, and came across the distribution
> sets (e.g., base.txz, src.txz) used by the installer to populate new
> file systems. I’d like to discuss switching these to .tzst (tar +
> zstd) compression.
>
> While I haven’t yet conducted detailed benchmarks comparing zstd and
> xz specifically for this use case, here are some initial
> considerations:
>
> Pros of zstd:
> - Faster compression and decompression speeds.
> - Aligns with the compression method used for FreeBSD packages.
>
> Cons of zstd:
> - Somewhat larger compressed file sizes.
> - Requires updates to tools that interact with distribution sets.
> - May have limited availability on some other operating systems (?).
>
> I have a review open to demonstrate the extent of the change in the
> build system & installer: https://reviews.freebsd.org/D48042
>
> It might be that this is not worth pursuing, as dist sets will most
> likely go away with the migration to pkgbase, but I would like to
> discuss and make an explicit decision. We can separately consider
> compression on the release media images themselves.
>
> Feedback Requested:
>
> Is there support for this idea? Are there objections to pursuing this?
> Are there other factors I should consider, especially compatibility concerns?

Even with a good internet connection, I usually find that downloading
the tarballs is slower than decompressing them.  So I vote to stick
with xz.