macos-storage-management

Measure the live Data volume with df -h "$HOME", rank large directories with du, and classify candidates into movable archives, rebuildable caches, and app-managed stores. Move only verified inactive data to an external drive using hash-checked copies before deleting any source files.

First detect File Provider placeholders using ls -lO@ and stat: files with dataless flags and zero blocks are not resident. Archive only resident regular files with SHA-256 verification, and leave placeholders untouched since deleting them removes cloud originals without reclaiming local space.

System Data is a classification bucket, not a folder. Check APFS snapshots, Time Machine local snapshots, app containers, caches, developer runtimes, and /private/var/folders with allocated-block measurements to find the real consumers before deleting anything.

ExFAT does not preserve macOS symlinks, permissions, extended attributes, or resource forks, so direct copies of app bundles or Git trees lose metadata. Use an uncompressed PAX tar archive with a manifest on ExFAT, and verify hashes before removing sources.

Docker.raw is a sparse disk, so compare its logical size with allocated blocks first. Use docker system df -v to attribute usage, remove retired projects in dependency-safe order, and never run docker system prune --volumes blindly or delete Docker.raw manually.

This error signals cloud-only placeholder files in a File Provider tree that cannot be opened locally. Stop retrying bulk copies, inspect dataless flags and allocated blocks, and switch to a resident-only archiving strategy that skips placeholders.