Dovecot vmail file watches limit

Edity /etc/sysctl.conf then add:

fs.inotify.max_user_watches=1000000  # or other number depend on your system

fs.inotify.max_user_instances = 1024 # not sure this is necessary


Use rsync to synchronize directories/backup

rsync -rtvlz –progress –size-only /home/    /media/usb_disk/home/back_up/

-r copies also all subdirectories within main directory
-t preserves modification times
-v verbose mode, shows more information
-l copies symbolic links
-z compresses files for faster transfer
–progress shows progress during transfer
–size-only compare files based on their size instead of hashes (less CPU, so faster)