You can just back up to the two 870 SSDs with TM and keep one offsite. It takes care of doing the correct incremental backup to each one automatically. Do not use the USB port on any router for this, those connections are very unstable and will corrupt backups. You can get a cheap Synology NAS with two ports, they usually support TM just fine. It's very convenient though due to the inherent risk with interrupting network connections at least one external backup is good to have. I use my NAS for offsite backups, it just replicates the locally stored TM backup over the internet to another NAS someplace else. You can get the Synology and fill it with 2x 4TB Crucial MX500 SATA SSDs. Wouldn't be my preferred choice as I still think NVMe M.2 SSDs are more reliable but they are the cheapest 5 year warranty SSDs out there.
Though only have the MBP really, am also very much liking the NAS idea, it backing TM w/out interaction on my part (it's all it needs for me to do). Today, went to couple big box stores to inform myself about Synology specifically, basically the staff had little knowledge and relied on ChatGPT. NAS appears a niche market in my town so I'm stuck with a couple basic Q. hopefully you have time as I'm coming to the conclusion of this thread:
1.
NAS will blow my budget many times over BUT following your last reply, I've looked at Synology's plethora of models and believe I've identified the following with some affordability and my very basic needs.
DS223j (€200) OR
DS223 (
€270). Both 2 bay 2"5 or 3"5. Wish they had small model only for 2"5. Looking at the specs I've a gut feeling the DS223 would be ultimately better value.
2.
Basic connection I run 3x older Linksys Velop tri-band mesh set-up for WiFi (100/40MBPS) Only the master node is interesting for reliability. It has 2x RJ45 ports, one via ethernet cable to the ISP's basic modem, other port to the 4k TV. IF I use a Y-splitter, keeping the TV hardwired, other end hardwired into the NAS, is that all there is to it? The NAS wired into the Velop and I have TM backup access via WiFi to my MBP?
3.
Bundles I know we talked about NVMe, T7s, 2"5, MX500 but not 3"5 HDD for TM. Amazon.de also has 3 bundled options (albeit HDD) with the DS223 between
€530-€550
A. DS223 + 2x 4TB WD RED Plus HDD
B. DS223 + 2x 4TB Seagate IronWolf NAS HDD
C. DS223 + 2x 4TB WD Red+ fitted/ tested with SE DSM installed (whatever that means)
OR
D. DS223 + 2x 4TB MX500 =
€680
What do you think? Stay well clear of all three 3"5 HDDs in absolute favour of the 2 x MX500 option?
Thanks for your patience with this.