On 23.01.23 15:00, Michael Adler wrote:
> This patch enables ISAR to build zstd compressed images.
>
I was briefly thinking you had solved the dpkg vs. zstd issue - just a
dream :)
Hi Jan.
I think you are speaking about zstd compression for the debian package that is 1% bigger but 13x times faster in expanding. [1]
Ubuntu and Arch adopted zstd but not debian which is still using xz and as far as I have seen neither in parallel using option -T.
I think you should ask them to produce all package with
export XZ_DEFAULTS='-T 8'
and enabling dpkg to set internally
XZ_DEFAULTS='-T 0'
unless it is differently set. What Do you think about changing ISAR to use zstd or xz -T without repackaging everything at fetch time?
It would be a solution: fetch, repackage with zstd and the downloads remain for a long time like a permanent cache and also the benefits.
The counter effect is that those debian packages and those produced by ISAR will be not anymore compatible with a standard debian and this could be a nasty surprise in some cases for some users.
The alternative is to repackage everything with xz parallel. Usually a modern laptop has 8 pipes but I have the sensation that with -T 0 it counts just the cores because on my machine spawn 4 not 8.
Best regards, R-