You have a lot of risk with this approach.
3-2-1 backup is the guide today:
3 copies of the data
2 different media
1 copy is off-site
Now I overlook the 2 different media requirement. I just keep 3 local copies on 3 different devices, and one online (look at Backblaze/storj.io or another provider).
So, Dr. Pepper? 😁
(I don't really know, never tasted this coke).
What do you mean by "possibility to upgrade storage other than just replacing drives with bigger ones"
That's pretty much all you can do with a fixed number of drive slots.
Today's NAS's use some form of ZFS/BTRFS, so they're really good at handling new drives. Though I think dynamic expansion is just coming on line in the latest versions, and may not be in production just yet
I can't speak to NAS, I've always "rolled my own" because no one makes what I want, let alone in a price point I can manage (I like to use 2.5" drives with a moderately powerful system as a media center/home server, etc, for compactness). My current box is an old small-form-factor desktop that maxes out at 3 drives, though I have 5 shoved into it.
For photos I use Syncthing (specifically Syncthing-Fork as it has more flexibility) on my phones to sync the DCIM folder to an always-on machine at home.
My DCIM folder syncs to a folder in my user profile on the server, other people sync to their respective folders. I permit this sync job to run in any network, with any power (AC or battery), so I never lose pictures I take.
This has a benefit of enabling me to manage photos from a pc, and those changes sync back to my phone (I generally move the photos out of the synced folder to somewhere else, this has the effect of removing them from the phone). Just don't use the built-in photo backup sync job, which only syncs photos from phone to PC.
Nice thing about Syncthing is you can sync anything anywhere however you want. Windows, Linux, Max, iOS (using Möbius).
I currently sync hundreds of gigs between several phones and several PCs. I have about a dozen sync jobs (folders in SyncThing terms). I also sync other folders from phones, to enable file management from a PC, since changes will be synced back with two-way sync jobs.
The MDM APIs in android land are a hot mess
Ain't that the truth.
I avoid Google stuff, actually going Google free on the phone I'm setting up now, so Family Link is out for me. And I try to avoid all-eggs-in-a-basket anyway.
Yea, it sucks. I've looked at a LOT of MDM for Android.
Hmm, I couldn't find that anywhere. Thanks again.
Oh, cool. Thanks for the recommendation!
What's Activity Watch do?
I looked at Github, by like so many projects there, the descriptions vary from minimal to non-existant.
For phone, a couple things.
Look for Mobile Device Management. I've been meaning to do this for family for years.
Flyve is an open source MDM. I've only tested it so far. You may want to look around for others.
To help with file management on Android, I setup sync jobs between the phone and a desktop (or a user's laptop) for certain folders, things like DCIM, Download, Movies, Pictures, etc (and certain app data folders such as Camscanner) using Syncthing-Fork on the phone, and Syncthing or SyncTrayzor on a pc. Doing this enables file management from the pc, as changes can sync back to the phone (and since I want my photos on my pc anyway...). Syncthing can work across most any network, including the internet and your phone data plan (so don't let it sync big stuff using data). It can be locked with a password too, to prevent little hands from mucking things up.
You could, in theory, just let it sync the entire sdcard, but lots of stuff changes all the time, such as app data in the Android folder. No reason to sync that stuff. Plus doing that doesn't permit finer control of sync for things like DCIM, which I permit to sync over any network and any power state.
Syncthing also works between two or more phones, or PCs (windows or Linux), and has lots of flexibility for sync. I use it extensively to share stuff with friends so we don't have to think about sharing, especially for larger files. I sync files between phones with no PC, some sync jobs use a pc as intermediary so both phones don't need to be connected all the time, etc.
Another sync tool, Resilio, is really good. But on the phone it's a major memory and battery hog, so I use it only for it's selective Sync feature, and keep it turned off otherwise.
These are just my ideas, everyone's use-case is different. Your problem is one I've been lazily working on for years, so I look forward to the other ideas that come up here.
Like the "face" on mars
I never knew Boston was designed for cars (yes, that's sarcasm, Boston is known for its roads being enlarged footpaths dating back hundreds of years, some of which started as paths that animals took).
The US is much more complex than such a simple statement. US cities, historically, weren't so much designed as grew. And I still see that today. My town, a suburb of a city, was established about 1860 (140 years ago), when there was empty space between it and the city - farmland.
It certainly wasn't "designed for cars" that didn't exist at the time. The town I grew up in existed before cars.
And I've seen this all over the place. The cities grow until they run into small towns, which then become suburbs of the city. These small towns were often agriculture based (or manufacturing based), because farms need to take their cop to the train, the train stop ends up growing a town.
The only "designed" city I can think of is one in Maryland. There are others, but cities aren't "designed" - that implies an over-arching plan. Cities are organic, they grow.
If you want to make a "design" argument, Western Europe is much more in line with this idea, since so much infrastructure was destroyed by two successive world wars over 20 years, and the reconstruction with "modern" engineering and design that took place starting in the 1950's.
Have you checked with Lineage? That's the most likely source.
Samsung phones are complex - if it can be unlocked depends on the exact model number (not just A15, there are often separate versions of each model).
Generally, US versions aren't unlockable or flashable. Generally.
I gave up on Samsung several years ago because I got tired of fighting to do anything. Even the unlock and flash procedures were a pain.