Failed to reduce SONiC VS Build size with option BUILD_REDUCE_IMAGE_SIZE in 202305 release

[thovikeerthi]

Hi Team,
In reference to 202305 commit (#16948), I attempted to generate reduced SONiC NOS VS VM image using build option 'BUILD_REDUCE_IMAGE_SIZE'. But noticed that, the final image size is same as earlier (i.e. as before using this build-option).

Request to please confirm, does this build option is supported/applicable for SONiC VS VM image (sonic-vs.img.gz) or not in 202305 release ?

Steps followed:
Step1: Clone 202305 source code (31-10-2023)
Step2: enable 'BUILD_REDUCE_IMAGE_SIZE' in '~/sonic-buildimage/rules/config' file
Step3: Follow normal build options to generate 'sonic-vs.img.gz' binary.
- make init
- make configure PLATFORM=vs
- make target/sonic-vs.img.gz

[gechiang]

@Staphylo please help guide whether your PR should work on 202305 or something else is required?

[thovikeerthi]

Hi @Staphylo , Please share your inputs/comments on the reported issue. If you have any recommendations, then would try with those options.

[Staphylo]

Hi @thovikeerthi sorry for the late reply I was unavailable recently.
The mechanisms I implemented behind BUILD_REDUCE_IMAGE_SIZE are mostly generic to all platform images.

I would have expected these savings to also be visible on sonic-vs.img but they might not be that meaningful.
This setting is therefore supported for sonic-vs.img but did not check if there was any savings on this image.

The space reduction has only been tested on Arista physical products which use Aboot.
This means that it might not work for ONIE based systems (like sonic-vs.img) though I doubt it.
A lot of the savings comes from file deduplication, however since the sonic-vs.img is a qcow2 image it is possible that it was already performing some dedup.

[thovikeerthi]

Hi @Staphylo,
Okay. Thanks for the clarification.