For my workstation I'm using a small script that packs and compresses all relevant directories with tar once a week. The resulting file is then copied to a local backup drive and to my NAS. An encrypted version of that file is sent to an offsite VPS.
For my selfhosted services (on Proxmox) I'm using ProxmoxBackupServer.
I've purposely build that NAS around two or three years ago. It's a Gigabyte B360M D3H mainboard, Intel Pentium Gold G5400 and 16GB of the cheapest RAM I could find. An Adaptec 71605 card provides SAS/SATA connections for up to 16 drives and a Mellanox Connect-X3 connects my NAS via 10Gbit/s to my network. The case is an Inter-Tech IPC 4U-4424 . It has 24 hot swap bays. But I would not recommend it because the backplane is terrible. Four or five slots are not working. Sometimes, when I re-insert a drive, it is not detected.
Using cheap RAM bit me in the ass last year as one of the RAM sticks started to fail. I didn't notice that there is a problem with the RAM at first. Only when I observed that one of my scripts was not working I started to investigate the problem. Turns out that one of the RAM sticks failed. Re-inserting the stick did not resolve the problem so I replaced all sticks with old Crucial RAM I had laying around. Some files that I transfered to the NAS during that time period are corrupt. In the future I won't use cheap RAM anymore and I'm also currently planning to replace the mainboard and CPU with something that supportes ECC RAM so that I can be notified when on of the sticks starts to fail.
I believe I could reduce the power consumption by ~50W-60W by replacing the R730 with a modern "consumer" mainboard + CPU. But I need two power supplies (I had some issues a few months ago with my UPS) and iDRAC/IPMI is so convenient that I don't want to miss it anymore.
I'm also currently searching for something power efficient to replace the Pentium in my NAS. Reason for that are some problems with bad RAM a year ago. ECC RAM would be nice to have, so that I can be notified when a RAM stick goes bad. I currently do not know for how long the old RAM stick was bad and which files may be corrupted because of that (I do not use a checksumming file system such as ZFS or BTRFS on my NAS).
Thanks. I will look into that.