[sneak]

It looks like he’s using HFS or APFS. These filesystems still lack data checksums for data on disk, aside from any of the other issues he ran into.

The only sane way to deal with unique/irreplaceable data (i.e. one’s own photos) where the authoritative copy is on a mac is to make several independent copies, with several kept offline, and assume that the macOS or Adobe’s terrible house of cards that is the creative suite is going to fuck everything up at some point.

I say this as someone with >1000GiB in a Lightroom catalog, run on a mac.

I have a copy on an always-connected external disk (made with rsync && rsync -c), a copy on a ZFS NAS (made with rsync && rsync -c user@host:), a Time Machine backup that is only connected weekly, and an offsite rsync to a USB drive, with a SHASUMS file sidecar.

I also copy the RAWs into the LR masters photo structure when I import them, and they go first from the camera into a Syncthing folder (pre-import) that is immediately and automatically replicated onto four machines in three buildings (two of which are ZFS with autosnapshots).