In an environment where the boot routine did not offer the customary option to boot to console – and where things such as Control-Alt-F2 were ineffective …
/etc/ttys
I experimented with making a comment of the line for ttyv8. So for example:
# Virtual terminals
ttyv1 "/usr/libexec/getty Pc" xterm on secure
ttyv2 "/usr/libexec/getty Pc" xterm on secure
ttyv3 "/usr/libexec/getty Pc" xterm on secure
ttyv4 "/usr/libexec/getty Pc" xterm on secure
ttyv5 "/usr/libexec/getty Pc" xterm on secure
ttyv6 "/usr/libexec/getty Pc" xterm on secure
ttyv7 "/usr/libexec/getty Pc" xterm on secure
# ttyv8 "/usr/local/bin/xdm -nodaemon" xterm off secure
That did not have the desired effect …
PC-BSD
[gjp4@cces3-gjp4-pc-bsd-ergovista621] ~% cat /etc/rc.conf.pcbsd | grep -i pcdm
# Enable the pcdm display manager
pcdm_enable="YES"
[gjp4@cces3-gjp4-pc-bsd-ergovista621] ~%
– changing the YES to NO was effective.
FreeBSD
If there's a display management line in /etc/rc.conf you can make a comment of it, e.g.
# kdm4_enable="YES"
– or change the YES to NO.