[PATCH 0/2] Improving apt cache

[Uladzimir Bely <ubely@ilbers.de>]

Currently, apt cache (e.g. `var/cache/apt/archives`) import and export
functions are not optimal. Multiple files are imported from global
DL_DIR to package WORKDIR, increasing disk IO and size needed.

Also, various chroots (bootstrap, buildchroot, sbuild chroot) include
their apt caches to sstate cache files.

This patchset switches to hardlinks instead of copies and removes apt
cache from bootstrapped images.

Currently (measured on qemuarm64-bullseye cross-compilation with
maximum 8 parallel tasks (e.g. 8 CPU cores)):
- build directory size reduced from 8878 to 7594 MiB
- runtime maximum disk usage reduced from 16018 to 12479 MiB

TODO:
- cleanup other rootfs's (sbuild-chroot, buildchroot)
- deal with additional copying in sbuild routines

Uladzimir Bely (2):
  Use hardlinks in deb-dl-dir functions
  Clean apt cache from debootstrapped rootfs dirs

 meta/classes/deb-dl-dir.bbclass                     | 4 ++--
 meta/recipes-core/isar-bootstrap/isar-bootstrap.inc | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

-- 
2.20.1