diff --git a/ks4/seafile-gc.md b/ks4/seafile-gc.md
index 0c7450d..9cc057e 100644
--- a/ks4/seafile-gc.md
+++ b/ks4/seafile-gc.md
@@ -105,9 +105,23 @@ du -sh .../seafile/rootfs/opt/seafile/seafile-data/storage/blocks   # was 867 G
   file), then `zfs destroy data/containers/seafile@pre-gc`
 - re-enable the crontab (incus-copy leg first; its next refresh
   transfers the shrunken dataset)
-- **schedule GC** so this never regrows: quarterly maintenance window
-  (offline GC is the CE price); host-side cron via
-  `incus exec seafile -- ...` or a documented manual ritual
+- **recurring GC** (done 2026-08-27 design): the MySQL backend runs
+  GC *online* (verified — the runs printed "use online GC" and `-r`
+  ran with services up), so no stop/start is needed. Host crontab:
+  ```cron
+  # monthly dry-run report (cheap health check, read-only)
+  0 6 1 * * incus exec seafile -- sh -c "cd /opt/seafile/seafile-server-latest && ./seaf-gc.sh -D" >> /var/log/seafile-gc.log 2>&1
+  # quarterly real GC: blocks + trashed repos + fs objects
+  0 6 15 1,4,7,10 * incus exec seafile -- sh -c "cd /opt/seafile/seafile-server-latest && ./seaf-gc.sh && ./seaf-gc.sh -r && ./seaf-gc.sh -R" >> /var/log/seafile-gc.log 2>&1
+  ```
+  At the post-cleanup scale (~120 k live files) the full sequence is
+  minutes, not hours. Keep it clear of the 01:00/04:30/05:00 backup
+  slots.
+- 2026-08-27 follow-ups executed: 8 old libraries deleted by user →
+  trash emptied → `seaf-gc -r` purged their stores (18 m, blocks now
+  590 G, −277 G total); 4 pre-`GarbageRepos` husks removed manually;
+  Documents to be recreated from a local re-sync (retires its ~4.9 M
+  fossil commit objects → expected final ~600 k inodes)
 - re-decide seafile's S3 backup with real post-GC numbers:
   per-file restic redux if the object count collapses far enough,
   `zfs send | restic --stdin-from-command` otherwise