diff --git a/curiosrc/seal/task_trees.go b/curiosrc/seal/task_trees.go
index 8a178bd903f..7994c354aad 100644
--- a/curiosrc/seal/task_trees.go
+++ b/curiosrc/seal/task_trees.go
@@ -211,8 +211,6 @@ func (t *TreesTask) Do(taskID harmonytask.TaskID, stillOwned func() bool) (done
 }
 
 func (t *TreesTask) CanAccept(ids []harmonytask.TaskID, engine *harmonytask.TaskEngine) (*harmonytask.TaskID, error) {
-	// todo reserve storage
-
 	id := ids[0]
 	return &id, nil
 }
diff --git a/storage/paths/local.go b/storage/paths/local.go
index ccb41c2a2bb..b5689eb5d46 100644
--- a/storage/paths/local.go
+++ b/storage/paths/local.go
@@ -61,24 +61,25 @@ type statExistingSectorForReservation struct {
 	ft storiface.SectorFileType
 }
 
-func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservation) (fsutil.FsStat, error) {
+func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservation) (stat fsutil.FsStat, newResvOnDisk int64, err error) {
 	start := time.Now()
 
-	stat, err := ls.Stat(p.local)
+	stat, err = ls.Stat(p.local)
 	if err != nil {
-		return fsutil.FsStat{}, xerrors.Errorf("stat %s: %w", p.local, err)
+		return fsutil.FsStat{}, 0, xerrors.Errorf("stat %s: %w", p.local, err)
 	}
 
 	stat.Reserved = p.reserved
+	var newReserveOnDisk int64
 
-	accountExistingFiles := func(id abi.SectorID, fileType storiface.SectorFileType) error {
+	accountExistingFiles := func(id abi.SectorID, fileType storiface.SectorFileType) (int64, error) {
 		sp := p.sectorPath(id, fileType)
 
 		used, err := ls.DiskUsage(sp)
 		if err == os.ErrNotExist {
 			p, ferr := tempFetchDest(sp, false)
 			if ferr != nil {
-				return ferr
+				return 0, ferr
 			}
 
 			used, err = ls.DiskUsage(p)
@@ -90,18 +91,19 @@ func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservat
 			if !os.IsNotExist(err) {
 				log.Warnf("getting disk usage of '%s': %+v", p.sectorPath(id, fileType), err)
 			}
-			return nil
+			return 0, nil
 		}
 
-		stat.Reserved -= used
-		return nil
+		return used, nil
 	}
 
 	for id, ft := range p.reservations {
 		for _, fileType := range ft.AllSet() {
-			if err := accountExistingFiles(id, fileType); err != nil {
-				return fsutil.FsStat{}, err
+			onDisk, err := accountExistingFiles(id, fileType)
+			if err != nil {
+				return fsutil.FsStat{}, 0, err
 			}
+			stat.Reserved -= onDisk
 		}
 	}
 	for _, reservation := range newReserve {
@@ -111,9 +113,11 @@ func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservat
 				continue
 			}
 
-			if err := accountExistingFiles(reservation.id, fileType); err != nil {
-				return fsutil.FsStat{}, err
+			onDisk, err := accountExistingFiles(reservation.id, fileType)
+			if err != nil {
+				return fsutil.FsStat{}, 0, err
 			}
+			newReserveOnDisk += onDisk
 		}
 	}
 
@@ -130,7 +134,7 @@ func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservat
 	if p.maxStorage > 0 {
 		used, err := ls.DiskUsage(p.local)
 		if err != nil {
-			return fsutil.FsStat{}, err
+			return fsutil.FsStat{}, 0, err
 		}
 
 		stat.Max = int64(p.maxStorage)
@@ -150,7 +154,7 @@ func (p *path) stat(ls LocalStorage, newReserve ...statExistingSectorForReservat
 		log.Warnw("slow storage stat", "took", time.Now().Sub(start), "reservations", len(p.reservations))
 	}
 
-	return stat, err
+	return stat, newReserveOnDisk, err
 }
 
 func (p *path) sectorPath(sid abi.SectorID, fileType storiface.SectorFileType) string {
@@ -198,7 +202,7 @@ func (st *Local) OpenPath(ctx context.Context, p string) error {
 		reservations: map[abi.SectorID]storiface.SectorFileType{},
 	}
 
-	fst, err := out.stat(st.localStorage)
+	fst, _, err := out.stat(st.localStorage)
 	if err != nil {
 		return err
 	}
@@ -280,7 +284,7 @@ func (st *Local) Redeclare(ctx context.Context, filterId *storiface.ID, dropMiss
 			return xerrors.Errorf("unmarshalling storage metadata for %s: %w", p.local, err)
 		}
 
-		fst, err := p.stat(st.localStorage)
+		fst, _, err := p.stat(st.localStorage)
 		if err != nil {
 			return err
 		}
@@ -404,7 +408,7 @@ func (st *Local) reportStorage(ctx context.Context) {
 
 	toReport := map[storiface.ID]storiface.HealthReport{}
 	for id, p := range st.paths {
-		stat, err := p.stat(st.localStorage)
+		stat, _, err := p.stat(st.localStorage)
 		r := storiface.HealthReport{Stat: stat}
 		if err != nil {
 			r.Err = err.Error()
@@ -445,14 +449,19 @@ func (st *Local) Reserve(ctx context.Context, sid storiface.SectorRef, ft storif
 			return nil, errPathNotFound
 		}
 
-		stat, err := p.stat(st.localStorage, statExistingSectorForReservation{sid.ID, fileType})
+		stat, resvOnDisk, err := p.stat(st.localStorage, statExistingSectorForReservation{sid.ID, fileType})
 		if err != nil {
 			return nil, xerrors.Errorf("getting local storage stat: %w", err)
 		}
 
 		overhead := int64(overheadTab[fileType]) * int64(ssize) / storiface.FSOverheadDen
 
-		if stat.Available < overhead {
+		if overhead-resvOnDisk < 0 {
+			log.Errorw("negative overhead vs on-disk data", "overhead", overhead, "on-disk", resvOnDisk, "id", id, "sector", sid, "fileType", fileType)
+			resvOnDisk = overhead
+		}
+
+		if stat.Available < overhead-resvOnDisk {
 			return nil, storiface.Err(storiface.ErrTempAllocateSpace, xerrors.Errorf("can't reserve %d bytes in '%s' (id:%s), only %d available", overhead, p.local, id, stat.Available))
 		}
 
@@ -798,7 +807,8 @@ func (st *Local) FsStat(ctx context.Context, id storiface.ID) (fsutil.FsStat, er
 		return fsutil.FsStat{}, errPathNotFound
 	}
 
-	return p.stat(st.localStorage)
+	stat, _, err := p.stat(st.localStorage)
+	return stat, err
 }
 
 func (st *Local) GenerateSingleVanillaProof(ctx context.Context, minerID abi.ActorID, si storiface.PostSectorChallenge, ppt abi.RegisteredPoStProof) ([]byte, error) {