If you experience problems, try the following:

First

• cat /etc/os-release to verify you are not, in fact, running Ubuntu Linux with a Plan 9 theme.

Boot

Boot parameters

• Immediately after the BIOS screen, hit any key until you see the > prompt. From there, values from plan9.ini may be temporarily added or changed (see 9boot(8)). When finished, type boot to resume booting.

Break into a shell

• At the [bootargs] prompt, type !rc and hit enter to break into a shell. Type exit to return to the [bootargs] prompt.

Editing plan9.ini

• It is not possible to edit plan9.ini stored on the cdrom, but parameters can be changed temporarily before booting. See above.
• On a harddrive installation, plan9.ini is stored with the bootloader and the kernel in a small FAT partition called 9fat at the beginning of the plan9 partition. The 9fat can be mounted by executing 9fs 9fat from the livecd or the installed system. The file /n/9fat/plan9.ini can then be edited with a text editor like acme(1), sam(1) or ed(1).
• If your change to plan9.ini or the 9fat made the system unbootable, it is always possible to manually override parameters on the > prompt (see above) or start the system from the livecd and pick your installed cwfs partition on the [bootargs] prompt (example: local!/dev/sdC0/fscache).

Boot media not recognized

• Break into a shell, then grep -n '^01' '#$/pci/'*ctl to get the pci vid/did of the installed disk controllers. then look in the sd drivers to see if the controller is already recognized.
• Sometimes, there is a problem with the drive, not the controller. cat /dev/sd*/ctl to get the status of the individual drives.
• Try different BIOS settings like AHCI/IDE mode.
• Try the USB troubleshooting steps (see below). Sometimes USB problems prevent unrelated devices from working properly.

I moved my hard drive between ports

• Don't do that.
• Let's assume it went from sdE0 to sdE1.
• At the bootargs prompt: local!/dev/sdE1/fscache -c
• filsys main c(/dev/sdE1/fscache)(/dev/sdE1/fsworm)
• filsys dump o
• filsys other /dev/sdE1/fsother
• end
• you're welcome.

Graphics

Rio fails to start

• Type the following to examine your card's supported VESA modes: aux/realemu; aux/vga -m vesa -p. Select an appropriate VESA mode and initialize: aux/vga -m vesa -l 1280x1024x32. (Replace 1280x1024x32 with the appropriate values.) When you find a working mode, update your plan9.ini.

Slow graphics refresh in rio

• Try the boot parameter *novesashadow=1.

Change graphics card without voiding the warranty

• http://www.datadocktorn.nu/us_kortbyte1.php

Networking

Cannot resolve domain names

• If ndb/dns is running but you are still unable to resolve domains, you can try adding a dns server directly to /net/ndb:

echo '    dns=8.8.8.8' >>/net/ndb

PCMCIA WiFi stopped working after reboot

• Power down completely with fshalt instead of just rebooting with fshalt -r.

USB

Devices not recognized or not working

• Break into a shell, or simply type in a rio window: ls /shr ls /dev/sdU* to list detected USB devices.
• Break into a shell, or simply type in a rio window: cat /dev/usbevent & and try plugging in a USB device. If the device is working at all, some output should appear on screen.
• If USB keyboard is the only option, try to enable PS2 emulation in the BIOS.

System freezes after showing memory sizes

• On multicore systems, remove the boot parameter *nomp=1 and add *msi=1.
• Try the boot parameter *nousbehci=1. (This disables USB 2.0.)
• Try the boot parameter *nousbuhci=1.