Dne 21. 12. 20 v 17:39 Neal Gompa napsal(a): > On Mon, Dec 21, 2020 at 11:29 AM Ben Cotton <bcotton@xxxxxxxxxx> wrote: >> # Decompression happens inline with download. This has a positive >> effect on resource usage: downloads are typically limited by >> bandwidth. Decompression and writing the full data into a single file >> per rpm is essentially free. Additionally: if there is more than one >> download at a time, a multi-CPU system can be better utilized. All >> compression types supported in RPM work because this uses the rpm I/O >> functions. >> # RPMs are cached on local storage between downloading and >> installation time as normal. This allows DNF to defer actual RPM >> installation to when all the RPM are available. This is unchanged. >> # The file format for RPMs is different with Copy on Write. The >> headers are identical, but the payload is different. There is also a >> footer. >> ## Files are converted (“transcoded”) locally during download using >> <code>/usr/bin/rpm2extents</code> (part of rpm codebase). The format I cannot find it anywhere in rpm codebase. >> # Disk space requirements are expected to be marginally higher than >> before: all new packages or updates will consume their installed size >> before installation instead of about half their size (regular rpms >> with payloads still cost space). The size is alreay an issue (for me) on small cloud images. But I do not use BTRFS there. So at the end I do not care :) >> >> Ballpark performance difference is about half the duration for file >> download+install time. A lot of rpms are very small, so it’s difficult >> to see/measure. Larger RPMs give much clearer signal. Hmm, I, personally, see much better perfomance (and storage) improvements in enabling %_minimize_writes however there is still https://bugzilla.redhat.com/show_bug.cgi?id=1872141 to be resolved before this got enabled by default. -- Miroslav Suchy, RHCA Red Hat, Associate Manager ABRT/Copr, #brno, #fedora-buildsys _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
