I reproduced this with Win10 x64 up to date on 4/11/2020 and the stock "quick create" versions of Ubuntu 18.04 and 19.10 as referenced and selected from the Hyper-V manager. Default options all the way. No updates installed after initial installation. This machine has AMD Ryzen 7 3800X and 32GB memory, NVMe SSD system drive -- it's fast. Default network adapter for the VMs. ipv6 enabled or disabled on underlying NIC and the vEthernet default switch (I tried both ways). 18.04 goes from "start" to X login in 11 seconds, including having to press through a console "error: no such device: root / press any key to continue" glitch. 19.10 goes from start to a Grub menu in about 3 seconds. 11 more seconds through console message about Spectre mitigation, then the Ubuntu splash screen of 5 dots on purple background, then console cursor holds for about 1:40. Then X login finally. System load during the long delay on network, disk, CPU under 5% during this time. Then suddenly a flurry of console messages followed by X login window. Seems very clear that the boot process is waiting for a long failed timeout somehow before proceeding.
By accident I discovered the following with 19.10. Select "system startup" from the grub menu. Result is Windows logo screen "Hyper-V UEFI / No boot devices were found." The "restart" button is not functional, have to "power off" the VM because "shutdown" fails. Re-power on without closing the connection window, and 19.10 proceeds through same sequence from "start" to X login in about 12 seconds: spectre mitigation message on console, Ubuntu splash, console cursor, then possibly the flurry of console messages (but so fast invisible), then X login. I can get through the sequence above of grub "system startup" then power-off, then restart to the X login from scratch in 25 seconds, whereas about 120 seconds if I just start and wait through the timeout. -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gdm3 in Ubuntu. https://bugs.launchpad.net/bugs/1848534 Title: [Microsoft Hyper-V guest] System shows graphic artifacts for a moment, then text cursor for about minute and then starts To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1848534/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs