Am Donnerstag, den 30.05.2019, 11:46 +0100 schrieb Dimitri John Ledkov: > On Thu, 30 May 2019 at 11:35, Dimitri John Ledkov <x...@ubuntu.com> > wrote: > > > > I see a lot of code in livecd-rootfs that tries hard to use lzma > > compression for the initaller (first-boot) initrd. > > On the classic, subsequent initrds get rebuild as gzip, and on core > > lzma persists. > > I do wonder what compression we should use by default for the > > installer media, Ubuntu Core, cloud images. > > > > Is the rationale for lzma installer initrds still valid? And what > > was > > it? Smallest size initrd? > > > > Note subiquity dropped using lzma for the installer image to improve > boot speed. > https://bugs.launchpad.net/subiquity/+bug/1750873 > > Which I find confusing from the spreadsheet graphs.... > gzip is fast at kernel, but not initrd > lzma fast at initrd, but not kernel > > As if lz4 kernel & xz initrd would yield the fastest boot time? That > sounds counter-intuitive. Unless for initrd, only the compressed size > matters and initrd decompression time does not matter? > > Measurements until break=bottom is reached would be nice. > > -- > Regards, > > Dimitri. >
I initially suggested lz4 support a few years back in LP #1488620. I do not have insight in all the projects at Canonical/Ubuntu and what is state of the art regarding compressors. If you ask me today I would recommend zstd, it is not intended to be as fast as lz4 and comparable high speed decompressors, but faster than lzma and gzip. I recently found 7-Zip zstd[1] while looking for a solution that supports zstd on Windows, may be the graphs in the project repository help you to find a better solution and learn about recently developed compressors. 1: https://github.com/mcmilk/7-Zip-zstd Best regards, Benjamin -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
