Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

Both DS220+ and DS224+ has been a pleasure to setup, but I wouldn't replace your DS218+ just because. Just make sure your RAID is healthy and your backup too.

An alternative to a standalone NAS is to setup your own little ITX server. Only if you enjoy tinkering though, Synology is definitely easier.
At home I'm currently running Server/NAS/Gaming PC all in one.
It's a Debian 12 KVM/QEMU host with an m.2 NVME disk for host OS + VM OS and 2x16TB Seagate Exos disks in RAID1 for data storage. The other hardware is a B650 ITX Motherboard, AMD Ryzen 7600 CPU, 2x32GB DDR5 RAM and AMD Radeon 6650 XT, Seasonic FOCUS PX 750W PSU.
With my KVM/QEMU host, Game Server and Jellyfin Server online it eats about 60W-65W, so not that bad.
The GPU and an USB Controller is passed through with VFIO to a virtual Fedora that I use as a desktop and gaming client.
Just make sure to have a sound dampening pc case so you can keep the servers online without being bothered. The GPU goes silent when the gaming VM is off.

Still running a ds210+ i bought second hand about 8 years ago.... Hosts a website and downloads torrents.. Not much else. Think it's about time i upgraded.

I had a DS212j for about 10 years before I replaced it, and it was working just fine, so I sold it on ebay. It just couldn't keep up with the transcoding plex that I was using it for. Heck, 7 of those years it was running on a shelf in my garage getting covered in dust, and spiderwebs.

I imagine a + model will last even longer than that.

It'll last long as it's useful to you barring any disasters. I've got a HP gen8 microserver that I've been running as a free/truenas box 8/9 years now and I'm only thinking of replacing it now as I need more performance than the CPU in it can give.

Had my Western Digital My Cloud since 2015.

Ah, I see you also choke yours with softwarr...

I have the same model as you and I also wonder when it will explode lol (mostly because I have it in my ROM and can hear when it is struggling).

I have it with lots of docker containers (I can't help it, it is my only server) and the drives never cease to spin.

I actually don't recall since when I have it but it must be similar as you as well...

Just as of recently started to do clean up of containers and such, mostly because I did a fuck up (I deleted with Portainer all my unused volumes which, strangely enough for me, got rid of Portainer's volume, I needed to recreate all my stacks/compose from portainer each one, so I cleaned up some stuff in the process).

At least 5 minutes.

shucked

oh you are dancing with the devil. not sure there's a way to check actual SMART data in Synology's OS but I would be very interested in those logs.

I've found over the years that the second I think about backing up the drive is about to fail.

I would update to a 4bay and invest in actual NAS drives. (and I will personally be looking for 10gbe lan but this isn't homelab)