ISOs with the new installer are 34% bigger than legacy ISOs

[Daniel van Vugt]

For example:
mantic-desktop-legacy-amd64.iso | 2023-07-18 09:06 | 3.8G (https://cdimage.ubuntu.com/daily-legacy/)
mantic-desktop-amd64.iso | 2023-07-18 08:28 | 5.1G (https://cdimage.ubuntu.com/daily-live/)

Slightly less severe in lunar:
ubuntu-23.04-desktop-legacy-amd64.iso | 2023-04-17 22:28 | 3.6G (https://cdimage.ubuntu.com/releases/23.04/release/)
ubuntu-23.04-desktop-amd64.iso | 2023-04-18 21:06 | 4.6G (https://releases.ubuntu.com/23.04/)

First reported in:
https://github.com/canonical/ubuntu-desktop-installer/issues/2253

[Daniel van Vugt (vanvugt)]

The difference seems to be in /casper/:

Legacy ISO:
2.7G filesystem.squashfs

New ISO:
1.3G minimal.standard.live.squashfs
2.5G minimal.squashfs

[Daniel van Vugt (vanvugt)]

Seems the problem is two copies of each snap in the one ISO:

minimal.standard.live.squashfs: /var/lib/snapd/seed/snaps

4.0K bare_5.snap
74M core22_817.snap
67M cups_980.snap
246M firefox_2916.snap
47M ghostscript-printer-app_769.snap
486M gnome-42-2204_120.snap
92M gtk-common-themes_1535.snap
39M gutenprint-printer-app_702.snap
62M hplip-printer-app_788.snap
4.1M ipp-usb_101.snap
46M ps-printer-app_1214.snap
54M snapd_19457.snap
452K snapd-desktop-integration_83.snap
13M snap-store_959.snap
129M ubuntu-desktop-installer_1153.snap
1.4G total

minimal.squashfs: /var/lib/snapd/seed/snaps

4.0K bare_5.snap
74M core22_817.snap
67M cups_980.snap
246M firefox_2916.snap
47M ghostscript-printer-app_769.snap
486M gnome-42-2204_120.snap
92M gtk-common-themes_1535.snap
39M gutenprint-printer-app_702.snap
62M hplip-printer-app_788.snap
4.1M ipp-usb_101.snap
46M ps-printer-app_1214.snap
54M snapd_19457.snap
452K snapd-desktop-integration_83.snap
13M snap-store_959.snap
1.2G total

The snaps haven't gotten any bigger compared to legacy, only duplicated.

[Michael Hudson-Doyle (mwhudson)]

I guess at some point in the construction of the minimal.standard.live layer, the /var/lib/snapd/seed/snaps directory got deleted and recreated. The way overlayfs represents this is not very helpful to the construction of minimal overlay squashfses :(

It seems I sort of predicted this situation in my comment here https://git.launchpad.net/livecd-rootfs/tree/live-build/lb_chroot_layered#n135

(on my list of things-i-want-to-look-at-but-have-never-got-around-to is seeing if rsyncing the layer into a fresh overlay is a better way of implementing reduce_pass_size)

[Michael Hudson-Doyle (mwhudson)]

https://code.launchpad.net/~mwhudson/livecd-rootfs/+git/livecd-rootfs/+ref/lp-2028213 is an attempt at a fix, testing in progress as I write this.

[Michael Hudson-Doyle (mwhudson)]

Ok that seems to work, so now proposed as https://code.launchpad.net/~mwhudson/livecd-rootfs/+git/livecd-rootfs/+merge/447749

[corrado venturini (corradoventu)]

A bigger ISO with less content! May be adding the missing apps the size will shrink.

[Daniel van Vugt (vanvugt)]

Same content actually. Just ~1.3GB of it was duplicated in two locations.

[Launchpad Janitor (janitor)]

This bug was fixed in the package livecd-rootfs - 23.10.8

---------------
livecd-rootfs (23.10.8) mantic; urgency=medium

  [ Heinrich Schuchardt ]
  * risc-v: increase loader2 partition for VisionFive 2. EDK II is available
    for the StarFive VisionFive 2 board. As it is larger than U-Boot we need
    to increase the size of the loader 2 partition to accommodate it.

  [ Michael Hudson-Doyle ]
  * lb_chroot_layered: use rsync to make more minimal overlay layers.
    (LP: #2028213)

 -- Michael Hudson-Doyle <email address hidden> Wed, 02 Aug 2023 13:19:29 +1200

[Daniel van Vugt (vanvugt)]

Looking good since the weekend:

4.2G mantic-desktop-amd64.iso
4.0G mantic-desktop-legacy-amd64.iso

[fossfreedom (fossfreedom)]

For Ubuntu Budgie our iso shrunk from 4.6G to 3.5G ... so nicely
done folks :)

On Mon, 7 Aug 2023, 03:20 Daniel van Vugt, <email address hidden>
wrote:

> Looking good since the weekend:
>
> 4.2G mantic-desktop-amd64.iso
> 4.0G mantic-desktop-legacy-amd64.iso
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/2028213
>
> Title:
> ISOs with the new installer are 34% bigger than legacy ISOs
>
> Status in livecd-rootfs package in Ubuntu:
> Fix Released
>
> Bug description:
> For example:
> mantic-desktop-legacy-amd64.iso | 2023-07-18 09:06 | 3.8G (
> https://cdimage.ubuntu.com/daily-legacy/)
> mantic-desktop-amd64.iso | 2023-07-18 08:28 | 5.1G (
> https://cdimage.ubuntu.com/daily-live/)
>
> Slightly less severe in lunar:
> ubuntu-23.04-desktop-legacy-amd64.iso | 2023-04-17 22:28 | 3.6G (
> https://cdimage.ubuntu.com/releases/23.04/release/)
> ubuntu-23.04-desktop-amd64.iso | 2023-04-18 21:06 | 4.6G (
> https://releases.ubuntu.com/23.04/)
>
> First reported in:
> https://github.com/canonical/ubuntu-desktop-installer/issues/2253
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/2028213/+subscriptions
>
>