I would probably use ntfy.sh for this purpose. It doesn’t quite meet all your requirements, but you could use a random channel name and get some amount of security…

You can self host it, or use the hosted version. (I know it’s technically not chat, but it works on a series of messages, it just happens to call them notifications.)

I don’t bother stopping services during backup, each service is contained to a single LVM volume, so snapshotting is exactly the same as yanking the plug. I haven’t had any issues yet, either with actual power failures or data restores.

The DMA doesn’t seem to have ever been about consumer choice, it’s about the choice of other competitors to have access to Apple’s customers without having to play by Apple’s rules. Just look at who was pushing for sideloading on iOS, I mostly saw Meta and Epic Games at the forefront. Why should Apple compromise my device’s integrity so that Meta can spy on me? I have no good answer to that.

My recommendation would be to utilize LVM. Set up a PV on the new drive and create an LV filling the drive (wit an FS), then move all the data off of one drive onto this new drive, reformat the first old drive as a second PV in the volume group, and expand the size of the LV. Repeat the process for the second old drive. Then, instead of extending the LV, set the parity option on the LV to 1. You can add further disks, increasing the LV size or adding parity or mirroring in the future, as needed. This also gives you the advantage that you can (once you have some free space) create another LV that has different mirroring or parity requirements.

See my other reply here.

Here are a few more details of my setup:

Components:

• server
• clients (phone/laptop)
• domain name (we'll call it custom.domain)
• home router
• dynamic DNS provider

The home router has WireGuard port forwarded to server, with no re-mapping (I'm using the default 51820). It's also providing DHCP services to my home network, using the 192.168.1.0/24 network.

The server is running the dynamic DNS client (keeping the dynamic domain name updated to my public IP), and I have a CNAME record on the vpn.custom.domain pointing to the dynamic DNS name (which is an awful random string of characters). I also have server.custom.domain with an A record pointing to 10.30.0.1. All my DNS records are in public DNS (so no need to change the DNS settings on the computer or phone or use DNS overrides with WireGuard.)

Immich config:

version: "3.8"

services:
  immich-server:
    container_name: immich_server
    image: ghcr.io/immich-app/immich-server:release
    entrypoint: ["/bin/sh", "./start-server.sh"]
    volumes:
      - ${UPLOAD_LOCATION}:/usr/src/app/upload
    env_file:
      - .env
    ports:
      - target: 3001
        published: 2283
        host_ip: 10.30.0.1
    depends_on:
      - redis
      - database
    restart: always
    networks:
      - immich

WireGuard is configured using wg-quick (/etc/wireguard/wg0.conf):

[Interface]
Address = 10.30.0.1/16
PrivateKey = <server-private-key>
ListenPort = 51820

[Peer]
PublicKey = <phone-public-key>
AllowedIPs = 10.30.0.12/32

[Peer]
PublicKey = <laptop-public-key>
AllowedIPs = 10.30.0.11/32

Start WireGuard with systemctl enable --now wg-quick@wg0.

Phone WireGuard configuration (iOS):

[Interface]
Name = vpn.custom.domain

Private Key = <phone private key>
Public Key = <phone public key>

Addresses = 10.30.0.12/32
Listen port = <blank>
MTU = <blank>
DNS servers = <blank>

[Peer]
Public Key = <server public key>
Pre-shared key = <blank>
Endpoint = vpn.custom.domain:51820
Allowed IPs = 10.30.0.0/16
Persistent Keepalive = 25

[On Demand Activation]
Cellular = On
Wi-Fi = On
SSIDs = Any SSID

This connection is then left always enabled, and comes on whenever my phone has any kind of network connection.

My laptop (running Linux), is also using wg-quick (/etc/wireguard/wg0.conf):

[Interface]
Address = 10.30.0.14
PrivateKey = <laptop private key>

[Peer]
PublicKey = <server-public-key>
Endpoint = vpn.custom.domain:51820
AllowedIPs = 10.30.0.0/16

My wife's window's laptop is configured using the official WireGuard windows app, with similar settings.

No matter where we are (at home, on a WiFi hotspot, or using cellular data) we access Immich over the VPN: http://server.custom.comain:2283/.

Let me know if you have any further questions.

If you want to change the name of the directory without breaking your volumes (or running services, etc), you can specify the name of the project inside the compose file

TiddlyWiki might be a good option. Technically it’s a wiki, but it is a single HTML page with all functionality built in JavaScript, you could host it on GH pages, though you wouldn’t be able to use its save feature there (you would have to save to your local machine and the deploy a new version). It stores text in little (or large) cards which can be given a title, tags and other metadata, and it providesa full search system.

Not that I’ve done this, but an IR sensor would probably work well.

I backup to a external hard disk that I keep in a fireproof and water resistant safe at home. Each service has its own LVM volume which I snapshot and then backup the snapshots with borg, all into one repository. The backup is triggered by a udev rule so it happens automatically when I plug the drive in; the backup script uses ntfy.sh (running locally) to let me know when it is finished so I can put the drive back in the safe. I can share the script later, if anyone is interested.

It’s been added recently, in the form of External Libraries.

Something that LVM supports but ZFS and BTRFS don’t, is the ability to reduce your storage. (That is, to empty and remove a drive from the array, without having to completely destroy the storage array.) As a home user without sufficient storage to have complete duplicates of everything, I find this an important feature.