Sync remote folders on Linux

csync is a file synchronizer especially designed for you, the normal user.

csync is a library and ships commandline client by default. It is server-less and allows synchronisation through either sftp or samba.

Usage examples:

csync /home/csync smb://csync:[email protected]/Users/csync
csync /home/csync sftp://[email protected]:2222/home/csync

I think you should solve your problems with rsync, that is the tried and true" syncronization tool for unixes.

rsync -uav --delete /loal/path example.com:/remote/path

Note: For bidirectional sync, you can use unison as well as csync.

This is how I would do a unidirectional sync with bare tools.

At the onset, tar the entire set of files and copy them to the destination point.
Also, setup a marker in the base directory.

touch /Source/base/directory/last-sync-time.txt

Now, we want to keep sync'ing from Source to Destination.

At the next time slot for syncing forward (from Source to Destination),

# The backup script
cd /Source/base/directory
tar cfj -N ./last-sync-time.txt backup.tar.bz2 .
scp backup.tar.bz2 user@backup-server:/Backup/Directory/
touch /Source/base/directory/last-sync-time.txt
rm -f backup.tar.bz2

1. The -N ./filename tells tar to archive only files modified or created after filename was modified/created.
   • Using a local reference for time confirms you make no mistake; if a backup was not taken for some reason, the next one will accumulate it
   • You can setup this script as a cronjob entry on the Source machine
   • I am assuming you will use scp with public key authentication
   • Also assuming you can reach the backup-server whenever this script is issued.
   • To be safer, you can add checks for confirming backup was stored and then, issue the touch command
   • You can choose to also insert commands to expand the backups overlaying them over previous ones at the Destination point; Or, keep incremental tar.bz2 archives.