I’ve been making copyparty, and one of the initial inspirations/usecases was exactly this one – bunch of internet-friends meeting in meatspace for some event, and needing to stream across pics/vids before we split up and maybe never meet again :-)

You can run the server on android using termux; see the instructions in the readme for the installation part, and then run the server like so: copyparty -e2ds --qr -v /storage/emulated/0/Pictures/from-family/::w

it will show a QR-code which you can scan from the other device to start uploading, and the folder is shared write-only (:w instead of :rw), so nobody can download anything. And it keeps track of which files have already been transferred, so the client will skip across dupes without reuploading them, and also resume interrupted uploads automatically.

Tried sending 340 photos (1.21 GiB) from an old iPhone to an android hotspot just now; I turned off the iPhone screen as soon as it started sending, and it finished in 41 seconds, so around 30 MiB/s? Maybe there are faster alternatives… But my javascript should be fairly resilient and recover from network glitches and such, so uploading from safari like this should be fine.

Not proxmox-specific, but I’ve been using btrfs on my servers and laptops for the past 6 years with zero issues. The only times it’s bugged out is due to bad hardware, and having the filesystem shouting at me to make me aware of that was fantastic.

The only place I don’t use zfs is for my nas data drives (since I want raidz2, and btrfs raid5 is hella shady) but the nas rootfs is btrfs.