I dont need a backup system. I just need a standardized way to keep 25 years of photos for a family of 4 with their own phones, cameras, downloads, scans etc. I still haven't found anything good.
I'm trialing a NAS with Immich, and then backing up the media and Immich DB dump daily to AWS S3 Deep Archive. It has Android and iOS apps, and enough of the feature set of Google Photos to keep me happy.
You can also store photos/scans on desktops in the same NAS and make sure Immich is picking them up (and then the backup script will catch them if they get imported to Immich). For an HN user it's pretty straight-forward to set up.
Is '25 years of photos' a North American measure of data I was previously unfamiliar with?
As bambax noted, you do in fact need a backup system -- you just don't realise that yet.
And you want a way of sharing data between devices. Without knowing what you've explored, and constraints imposed by your vendors of choice, it's hard to be prescriptive.
FWIW I use syncthing on gnu/linux, microsoft windows, android, in a mesh arrangement, for several collections of stuff, anchored back to two dedicated archive targets (small memory / large storage debian VMs) running at two different sites, and then perform regular snapshots on those using borgbackup. This gives me backups and archives. My RPO is 24h but could easily be reduced to whatever figure I want.
I believe this method won't work if Apple phones / tablets are involved, as you are not allowed to run background tasks (for syncthing) on your devices.
(I have ~500GB of photos, and several 10-200GB collections of docs and miscellaneous files, as unique repositories - none of these experience massive changes, it's mostly incremental differences, so it is pretty frugal with diff-based backup systems.)
Downloads and scans are generally trash unless deemed important.
For the phones and cameras, setup Nextcloud and have it automatically sync to your own home network. Then have a nightly backup to another disk with a health check after it finishes.
After that you can pick either a cloud host which your trust or get another drive of ours into someone else's server to have another locstion for your 2nd backup and you're golden.
I use syncthing... it's great for that purpose, Android is not officially supported but there is a fork, that works fine. Maybe you want to combine it with either ente.io or immich (also available for self-hosted) for photo backup.
I would also distinguish between documents (like PDF and TIFF) and photos - there is also paperless ngx.
I’ve tried Möbius before but wasn’t happy with it. Ended up switching to Resilio Sync (proprietary, one-time purchase) some years ago; the iOS client was better, it synced faster, and it was better at working around NAT/FW issues.
But I recently tried Syncthing again, and it seems to have mostly catches up except for the iOS client.
PhotoPrism or Immich are solid self-hosted options that handle deduplication and provide good search/tagging for family photos. For cloud, Backblaze B2 + Cryptomator can give you encrypted storage at ~$1/TB/month with DIY scripts for uploads.
Others have already mentioned Syncthing[^1]. Here's what I'm doing on a budget since I don't have a homeserver/NAS or anything like that.
First you need to choose a central device where you're going to send all of the important stuff from other devices like smartphones, laptops, etc. Then you need to setup Syncthing, which works on linux, macos, windows and others. For android there's Syncthing-fork[^2] but for iOS idk.
Setup the folders you want to backup on each device, for android, the folders I recommend to backup are DCIM, documents, downloads. For the most part, everything you care about will be there. But I setup a few others like Android/media/WhatsApp/Media to save all photos shared on chats.
Then on this central device that's receiving everything from others, that's where you do the "real" backups. I my case, I'm doing backups to a external HDD, and also to a cloud provider with restic[^3].
I highly recommend restic, genuinely great software for backups. It is incremental (like BTRFS snapshots), has backends for a bunch of providers, including any S3 compatible storage and if combined with rclone, you have access to virtually any provider. It is encrypted, and because of how it was built, can you still search/navigate your remote snapshots without having to download the entire snapshot (borg[^4] also does this), the most important aspect of this is that you can restore individual folders/files. And this crucial because most providers for cloud storage will charge you more depending on how much bandwidth you have used. I have already needed to restore files and folders from my remote backups in multiple occasions and it works beautifully.
Also external "slow" storage drives are fairly inexpensive now as a third backup if your whole life's images and important documents are at stake.
Always best to keep multiple copies of photos or documents that you care about in multiple places. Houses can flood or burn, computers and storage can fail. No need to be over-paranoid about it, but two copies of important things isn't asking too much of someone.
I recently found that Nextcloud is good enough to "collect" the photos from my family onto my NAS. And my NAS makes encrypted backups to a cloud using restic.
