There are two mistakes in the advice offered. One is major: the rule
in /etc/udev/rules.d/ has to be used after 80-udisks.rules in
/lib/udev/rules.d, so would be better put in 85-no-automount.rules. A
relatively minor mistake (which was reported in your syslog) is that
'subsystem' should be 'SUBSYSTEM'.
It should be sufficient to leave out 'ACTION' and 'SUBSYSTEM' and have
the rule as:
ENV{UDISKS_AUTOMOUNT_HINT}="never"
or
ENV{UDISKS_PRESENTATION_NOPOLICY}="1"
The latter is used in 80-udisks.rules.
Dear Brian,
Thank you for your help. However, I still don't have luck.
I followed your advice and
1) renamed the custom rules file to
/etc/udev/rules.d/85-no-automount.rules
2) upcased subsystem key.
The rule, therefore, looked like this:
ACTION="add|change", SUBSYSTEM=="block", ENV{UDISKS_AUTOMOUNT_HINT}="never"
Following a suggestions in another message on this thread, I also tried
replacing '=' with '==' after the ACTION and ENV{...} keywords.
**Still no luck.**
With Thunar/Thunar-volman neither rule prevents automounting but, as
they are only hints, a file manager may ignore them. Purging the
volume management software or setting Thunar to not use it is how I
would tackle the issue.
Thunar/Thunar-volume are not installed on my system.