Public bug reported: Release: Kubuntu 26.04.1 (resolute), desktop ISO, booted over PXE with boot=casper netboot=nfs
What happens: During boot, “Generating APT cache for cdrom” takes about 2½ minutes. After reading file:/cdrom, it repeatedly tries archive.ubuntu.com and security.ubuntu.com and fails with “Temporary failure resolving” until it gives up. Total boot to desktop is about 4 minutes, versus about 1½ with the fix below. Cause: scripts/casper-bottom/41apt_build_cache_cdrom (added for LP #2145807) removes everything from /root/etc/apt/sources.list.d except cdrom.sources, but doesn’t handle the legacy /root/etc/apt/sources.list, which in the 26.04 image contains: deb http://archive.ubuntu.com/ubuntu/ resolute main restricted universe multiverse deb http://security.ubuntu.com/ubuntu/ resolute-security main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ resolute-updates main restricted universe multiverse So apt-get update queries the internet mirrors as well. On optical or USB boot there’s no network at this stage, so the lookups fail instantly. On netboot the network is up, but DNS isn’t usable yet (/etc/resolv.conf points to the systemd-resolved stub, which isn’t running), so every lookup waits out a timeout. Fix: Also remove sources.list inside the overlay, before apt-get update: rm -f -- /root/etc/apt/sources.list chroot /root apt-get update --no-list-cleanup Since this runs on the temporary overlay of /etc/apt, the live system’s real sources.list is unaffected once the overlay is unmounted. Tested by adding the patched script as an extra initrd: the step now completes in seconds, and the live session and installer work normally. ** Affects: casper (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2173250 Title: casper: 41apt_build_cache_cdrom ignores /etc/apt/sources.list, stalling netboot for minutes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/casper/+bug/2173250/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
