Tested with Red Hat Enterprise Linux 6.9.

When inserting (USB) storag into a Red Hat Linux system all logged in users on the (default) Gnome desktop receive the following message:

To disable:

1. Check the current setting:

   sudo /usr/bin/gconftool-2 --direct \
   --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
   --get /apps/nautilus/preferences/media_automount

   This will show as “No value set for `/etc/gconf/gconf.xml.mandatory`” right after installation.

2. Set to disabled:

   sudo /usr/bin/gconftool-2 --direct \
   --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
   --type bool --set /apps/nautilus/preferences/media_automount false

Sources:

• LinuxQuestions.org - RHEL 6 - Disable Gnome DVD Automount
• Tips4Linux.com - Disable automount for removable devices in Ubuntu
• Gnome.org - GConf configuration system

According to LinuxQuestions.org - RHEL 6 - Disable Gnome DVD Automount this works on Red Hat Enterprise Linux 5:

/usr/bin/gconftool-2 --direct \
 --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \ 
 --type bool --set /desktop/gnome/volume_manage/automount_media false
 /usr/bin/gconftool-2 --direct \
 --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory \
 --type bool --set /desktop/gnome/volume_manager/automount_drives false