The kernel code path mentioned in #55 is only executed if there is no "early userspace init" - in other words, if there is no /init on initrd:
https://git.launchpad.net/~ubuntu- kernel/ubuntu/+source/linux/+git/bionic/tree/init/main.c?id=Ubuntu-4.15.0-47.50#n1087 /* * check if there is an early userspace init. If yes, let it do all * the work */ if (!ramdisk_execute_command) ramdisk_execute_command = "/init"; // <--- if there's no command specified, default to /init if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { // <-- check if /init is present by doing the access syscall ramdisk_execute_command = NULL; prepare_namespace(); // <-- call prepare_namespace as mentioned in #55 which results in an error } However, I can see that the initrd used in my case contains the init script (so sys_access should be successful): initrd=http://10.10.101.2:5248/images/ubuntu/amd64/generic/bionic/daily /boot-initrd lsinitramfs /var/lib/maas/boot-resources/current/ubuntu/amd64/generic/bionic/daily/boot-initrd | grep -P ^init$ init If I increase the memory allocation from 2048 to 2049 MiB the machine starts to boot just fine. Unsuccessful boot log (2048 MiB): https://paste.ubuntu.com/p/CY834ZGnvS/ Successful boot log (2049 MiB): https://paste.ubuntu.com/p/3fYfFXW8qR/ Attached boot-initrd. ** Attachment added: "boot-initrd" https://bugs.launchpad.net/maas/+bug/1797581/+attachment/5257069/+files/boot-initrd -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1797581 Title: Composing a VM in MAAS with exactly 2048 MB RAM causes the VM to kernel panic To manage notifications about this bug go to: https://bugs.launchpad.net/maas/+bug/1797581/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
