my_backup — kopia cache relocation (C: → D:)

Background

Surfaced from System-Maintenance’s C: purge (2026-07-21): kopia’s local cache was 11.83GB on C:\Users\Admin\AppData\Local\kopia (kopia’s OS default). Talbot approved moving it to D: to free SSD space for OS/apps.

What was done

• Kopia has no env var for cache dir (only KOPIA_PASSWORD, KOPIA_CONFIG_PATH, KOPIA_LOG_DIR are env-driven). Cache dir is set per-repository, persisted in each repo’s own kopia.config: kopia --config-file <repo>/kopia.config cache set --cache-directory=<path>.
• my_backup has 2 repos: Kopia_Active → D:/bak/KopiaCache/Active, Kopia_Static → D:/bak/KopiaCache/Static. No my_backup code change needed — setting lives in kopia’s own repo config, survives all future runs (uv/cron/Task Scheduler).
• Verified live: cache set triggers a full maintenance run (GC + compaction) against the new path — real-operation verification, not dry-run. Both new dirs populated immediately.
• Docs updated in my_backup repo (README, LESSONS, CHANGELOG), committed 0492612.
• Old C: cache (~12GB, including 9 orphaned repo-ID folders from past reconnections) deleted by Talbot per escalated Remove-Item command — IT charter requires CEO approval for deletions.
• Confirmed post-purge: C: went 11.8GB → 32GB → 59GB (aggressive app cleanup on top). Spot-check after next scheduled run confirmed D:\bak\KopiaCache\ grew, C: didn’t.

Result

Cache fully relocated to D:, C: reclaimed ~12GB+ from kopia alone. No ongoing action needed.