Ed Maste <emaste_at_freebsd.org> wrote on Date: Fri, 13 Dec 2024 21:15:45 UTC "
> 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. My notes are mostly not about the specific compression format --but are about the dist-sets potentially going away. I tend to use https://artifact.ci.freebsd.org/snapshot/*/*/*/*/*.txz for crude bisecting without needing to do builds. For example, grabbing something like: https://artifact.ci.freebsd.org/snapshot/main/926905796749750da6464b97ec4f8eec0882cc0e/arm64/aarch64/kernel.txz https://artifact.ci.freebsd.org/snapshot/main/926905796749750da6464b97ec4f8eec0882cc0e/arm64/aarch64/kernel-dbg.txz to see compare/contrast behavior with other builds. This also avoids questions about if my builds create any problems vs. official builds. > 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, I tend to use https://artifact.ci.freebsd.org/snapshot/*/*/*/*/*.txz for crude bisecting without needing to do builds. Are you saying that such will no longer be a possibility? (This is not a which-compression-style question.) I've also used the likes of the below with kgdb to look at reported backtraces from problems that have been reported --for versions of FreeBSD that I do not have a boot environment for. (Not wanting to do a normal install on other media and to boot/configure it --just to look around.) http://ftp3.freebsd.org/pub/FreeBSD/releases/amd64/14.2-RELEASE/kernel.txz http://ftp3.freebsd.org/pub/FreeBSD/releases/amd64/14.2-RELEASE/kernel-dbg.txz http://ftp3.freebsd.org/pub/FreeBSD/releases/amd64/14.2-RELEASE/src.txz (But there is no equivalent for patch revisions of *.*-RELEASE 's .) http://ftp3.freebsd.org/pub/FreeBSD/snapshots/arm64/13.4-STABLE/kernel.txz http://ftp3.freebsd.org/pub/FreeBSD/snapshots/arm64/13.4-STABLE/kernel-dbg.txz http://ftp3.freebsd.org/pub/FreeBSD/snapshots/arm64/13.4-STABLE/src.txz Similar question for those: no longer to be possible? > 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? === Mark Millard marklmi at yahoo.com
