On Remote Server

Add backuppc user

adduser backuppc
passwd backuppc
su - backuppc
From root run visudo to update sudoer
backuppc ALL=(ALL:ALL) NOPASSWD: /usr/bin/rsync, /bin/tar
Optional:
chmod 755 /home/backuppc/.ssh
chmod 600 /home/backuppc/.ssh/authorized_keys

On BackupPC server

Copy Public key from BackupPC server to remote host for passwordless login
ssh-copy-id backuppc@Remote_Host
ssh -c blowfish -q -x -l backuppc Remote_Host hostname
if it successfully return the remote hostname, we ready to add remote host to Backuppc Web Dashboard
http://mydomain.vn/backuppc -> Edit Config -> Host -> Add Host: Hostname, User: backuppc

Configure transfer method

Select the remote hostname from the list of Host

http://mydomain.vn/backuppc/index.cgi?host=Remote_Host -> Edit Config -> Xfer

XferMethod: Rsync
RsyncShareName: /var/www

Replace root user (after -q -x -l) with backuppc in RsyncClientCmdRsyncClientRestoreCmd

Leave Schedule as default