Linux KVM: OpenBSD Guest Hangs At Starting tty Flags

Posted on in Categories , , , , last updated May 6, 2017

OpenBSD version 4.5 and above made changes in kernel which prevents booting OpenBSD using KVM technology. OpenBSD 4.4 runs with mbbios enabled. However, due to some sort of bug in KVM it does not boot and hangs while displaying a message which read as “Starting tty flags”. The workaround is to disable mpbios. This may or may not happen with your installation, but if it hanged, use the following procedure.

Step # 1: Boot OpenBSD With -c Option

At boot> prompt type the following command:

bsd -c
disable mpbios
quit

Sample session:

Fig.01: OpenBSD KVM Hangs at setting tty flags workaround
Fig.01: OpenBSD KVM Hangs at setting tty flags workaround

Now OpenBSD will boot without any problem. Login as root and type the following command to disable mpbios permanently:

# config -ef /bsd
disable mpbios
quit

Sample session:

Fig.02: Disabling mpbios for OpenBSD running under Linux KVM
Fig.02: Disabling mpbios for OpenBSD running under Linux KVM

Now you can use OpenBSD without any problem. Please note that this problem only occured under RHEL 5.5 64bit (KVM83) running OpenBSD 4.7 64bit guest. The config command can be used to build kernel compilation directories or modify a kernel. In this case you’ve modified the kernel to boot without mpbios support. The mpbios driver extracts configuration information from the BIOS on multiprocessor systems that conform to the Intel MultiProcessor Specification. See config and mpbios man page for further information.

This entry is 13 of 14 in the CentOS / Redhat (RHEL) KVM Virtulization series. Keep reading the rest of the series:
  1. CentOS / Redhat: Install KVM Virtualization Software
  2. CentOS / Redhat: KVM Bridged Network Configuration
  3. KVM virt-manager: Install CentOS As Guest Operating System
  4. KVM virt-install: Install FreeBSD / CentOS As Guest Operating System
  5. KVM: Install CentOS / RHEL Using Kickstart File (Automated Installation)
  6. Troubleshooting KVM Virtualization Problem With Log Files
  7. KVM Virsh: Redirect FreeBSD Console To A Serial Port
  8. KVM: Starting / Stopping Guest Operating Systems With virsh Command
  9. Linux KVM: Disable virbr0 NAT Interface
  10. FreeBSD / OpeBSD Running in KVM Does Not Accept FTP Traffic
  11. KVM: Start a Virtual Machine / Guest At Boot Time
  12. KVM virt-install: Install OpenBSD As Guest Operating System
  13. Linux KVM: OpenBSD Guest Hangs At Starting tty Flags
  14. KVM Virtualization: Start VNC Remote Access For Guest Operating Systems

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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