It is about backing up iMac Late 2013 - it means the SSD is built-in and not removable. Currently Time Machine is used for backups. TM target storage is a NAS by QNAP. No mass storage is reliable, data disaster can happen every minute even if NAS with RAID array is used. It is critical in case of data collected by Time Machine - these are backups! In order to increase reliability the idea is to have additionally a TM data copy on separate external hdd/ssd. Will it be possible? Where to find appropriate instructions? Used NAS does also support Rsync Server and RTRR Server. Will any of them two be more suitable for backing up the iMac SSD?