One of my PC’s has ended up becoming a testing ground for a number of Linux distributions. The list has included openSUSE, Fedora, Arch and LMDE with Sabayon being the latest incumbent. From Arch onwards in that list though, a message has appeared on loading the desktop with every one of these when I have Dropbox’s client set up on there:
Unable to monitor entire Dropbox folder hierarchy. Please run “echo 100000 | sudo tee /proc/sys/fs/inotify/max_user_watches” and restart Dropbox to correct the problem.
Even applying the remedy that the message suggests won’t permanently fix the problem. For that, you need to edit /etc/sysctl.conf with superuser access and add the following line to it:
fs.inotify.max_user_watches = 100000
With that in place, you can issue the following command to fix the problem in the current session (assuming your user account is listed in /etc/sudoers):
sudo sysctl -p & dropbox stop & dropbox start
A reboot should demonstrate that the messages no longer appear again. For a good while, I had ignored it but curiosity eventually got me to find out how it could be stopped and led to what you find above.