diff --git a/manager.go b/manager.go
index f125cdafd..f4408b6e0 100644
--- a/manager.go
+++ b/manager.go
@@ -152,8 +152,10 @@ func (m *Manager) AddWorker(ctx context.Context, w Worker) error {
 	}
 
 	m.sched.newWorkers <- &workerHandle{
-		w:    w,
-		info: info,
+		w:         w,
+		info:      info,
+		preparing: &activeResources{},
+		active:    &activeResources{},
 	}
 	return nil
 }
@@ -171,84 +173,6 @@ func (m *Manager) ReadPieceFromSealedSector(context.Context, abi.SectorID, ffiwr
 	panic("implement me")
 }
 
-/*func (m *Manager) getWorkersByPaths(task sealtasks.TaskType, inPaths []stores.StorageInfo) ([]WorkerID, map[WorkerID]stores.StorageInfo) {
-	m.workersLk.Lock()
-	defer m.workersLk.Unlock()
-
-	var workers []WorkerID
-	paths := map[WorkerID]stores.StorageInfo{}
-
-	for i, worker := range m.workers {
-		tt, err := worker.w.TaskTypes(context.TODO())
-		if err != nil {
-			log.Errorf("error getting supported worker task types: %+v", err)
-			continue
-		}
-		if _, ok := tt[task]; !ok {
-			log.Debugf("dropping worker %d; task %s not supported (supports %v)", i, task, tt)
-			continue
-		}
-
-		phs, err := worker.w.Paths(context.TODO())
-		if err != nil {
-			log.Errorf("error getting worker paths: %+v", err)
-			continue
-		}
-
-		// check if the worker has access to the path we selected
-		var st *stores.StorageInfo
-		for _, p := range phs {
-			for _, meta := range inPaths {
-				if p.ID == meta.ID {
-					if st != nil && st.Weight > p.Weight {
-						continue
-					}
-
-					p := meta // copy
-					st = &p
-				}
-			}
-		}
-		if st == nil {
-			log.Debugf("skipping worker %d; doesn't have any of %v", i, inPaths)
-			log.Debugf("skipping worker %d; only has %v", i, phs)
-			continue
-		}
-
-		paths[i] = *st
-		workers = append(workers, i)
-	}
-
-	return workers, paths
-}
-
-func (m *Manager) getWorker(ctx context.Context, taskType sealtasks.TaskType, accept []WorkerID) (Worker, func(), error) {
-	ret := make(chan workerResponse)
-
-	select {
-	case m.schedule <- &workerRequest{
-		taskType: taskType,
-		accept:   accept,
-
-		ctx: ctx.Done(),
-		ret: ret,
-	}:
-	case <-m.closing:
-		return nil, nil, xerrors.New("closing")
-	case <-ctx.Done():
-		return nil, nil, ctx.Err()
-	}
-
-	select {
-	case resp := <-ret:
-		return resp.worker, resp.done, resp.err
-	case <-m.closing:
-		return nil, nil, xerrors.New("closing")
-	case <-ctx.Done():
-		return nil, nil, ctx.Err()
-	}
-}*/
-
 func schedNop(context.Context, Worker) error {
 	return nil
 }
diff --git a/sched.go b/sched.go
index 1a2efb5e7..78f2a6664 100644
--- a/sched.go
+++ b/sched.go
@@ -109,15 +109,22 @@ func (r *workerRequest) respond(err error) {
 	}
 }
 
+type activeResources struct {
+	memUsedMin uint64
+	memUsedMax uint64
+	gpuUsed    bool
+	cpuUse     uint64
+
+	cond *sync.Cond
+}
+
 type workerHandle struct {
 	w Worker
 
 	info storiface.WorkerInfo
 
-	memUsedMin uint64
-	memUsedMax uint64
-	gpuUsed    bool
-	cpuUse     uint64 // 0 - free; 1+ - singlecore things
+	preparing *activeResources
+	active    *activeResources
 }
 
 func (sh *scheduler) runSched() {
@@ -198,12 +205,8 @@ func (sh *scheduler) maybeSchedRequest(req *workerRequest) (bool, error) {
 		}
 		tried++
 
-		canDo, err := sh.canHandleRequest(wid, worker, req)
-		if err != nil {
-			return false, err
-		}
-
-		if !canDo {
+		needRes := ResourceTable[req.taskType][sh.spt]
+		if !canHandleRequest(needRes, sh.spt, wid, worker.info.Resources, worker.preparing) {
 			continue
 		}
 
@@ -240,99 +243,120 @@ func (sh *scheduler) maybeSchedRequest(req *workerRequest) (bool, error) {
 func (sh *scheduler) assignWorker(wid WorkerID, w *workerHandle, req *workerRequest) error {
 	needRes := ResourceTable[req.taskType][sh.spt]
 
-	w.gpuUsed = needRes.CanGPU
-	if needRes.MultiThread() {
-		w.cpuUse += w.info.Resources.CPUs
-	} else {
-		w.cpuUse++
-	}
-
-	w.memUsedMin += needRes.MinMemory
-	w.memUsedMax += needRes.MaxMemory
+	w.preparing.add(w.info.Resources, needRes)
 
 	go func() {
-		var err error
-
-		defer func() {
-			sh.workersLk.Lock()
-
-			if needRes.CanGPU {
-				w.gpuUsed = false
-			}
-
-			if needRes.MultiThread() {
-				w.cpuUse -= w.info.Resources.CPUs
-			} else {
-				w.cpuUse--
-			}
-
-			w.memUsedMin -= needRes.MinMemory
-			w.memUsedMax -= needRes.MaxMemory
+		err := req.prepare(req.ctx, w.w)
 
+		sh.workersLk.Lock()
+		err = w.active.withResources(sh.spt, wid, w.info.Resources, needRes, &sh.workersLk, func() error {
+			w.preparing.free(w.info.Resources, needRes)
 			sh.workersLk.Unlock()
+			defer sh.workersLk.Lock() // we MUST return locked from this function
 
 			select {
 			case sh.workerFree <- wid:
 			case <-sh.closing:
 			}
-		}()
 
-		err = req.prepare(req.ctx, w.w)
-		if err == nil {
 			err = req.work(req.ctx, w.w)
-		}
 
-		select {
-		case req.ret <- workerResponse{err: err}:
-		case <-req.ctx.Done():
-			log.Warnf("request got cancelled before we could respond")
-		case <-sh.closing:
-			log.Warnf("scheduler closed while sending response")
-		}
+			select {
+			case req.ret <- workerResponse{err: err}:
+			case <-req.ctx.Done():
+				log.Warnf("request got cancelled before we could respond")
+			case <-sh.closing:
+				log.Warnf("scheduler closed while sending response")
+			}
+
+			return nil
+		})
+
+		sh.workersLk.Unlock()
 	}()
 
 	return nil
 }
 
-func (sh *scheduler) canHandleRequest(wid WorkerID, w *workerHandle, req *workerRequest) (bool, error) {
-	needRes, ok := ResourceTable[req.taskType][sh.spt]
-	if !ok {
-		return false, xerrors.Errorf("canHandleRequest: missing ResourceTable entry for %s/%d", req.taskType, sh.spt)
+func (a *activeResources) withResources(spt abi.RegisteredProof, id WorkerID, wr storiface.WorkerResources, r Resources, locker sync.Locker, cb func() error) error {
+	for !canHandleRequest(r, spt, id, wr, a) {
+		if a.cond == nil {
+			a.cond = sync.NewCond(locker)
+		}
+		a.cond.Wait()
 	}
 
-	res := w.info.Resources
+	a.add(wr, r)
+
+	err := cb()
+
+	a.free(wr, r)
+	if a.cond != nil {
+		a.cond.Broadcast()
+	}
+
+	return err
+}
+
+func (a *activeResources) add(wr storiface.WorkerResources, r Resources) {
+	a.gpuUsed = r.CanGPU
+	if r.MultiThread() {
+		a.cpuUse += wr.CPUs
+	} else {
+		a.cpuUse += uint64(r.Threads)
+	}
+
+	a.memUsedMin += r.MinMemory
+	a.memUsedMax += r.MaxMemory
+}
+
+func (a *activeResources) free(wr storiface.WorkerResources, r Resources) {
+	if r.CanGPU {
+		a.gpuUsed = false
+	}
+	if r.MultiThread() {
+		a.cpuUse -= wr.CPUs
+	} else {
+		a.cpuUse -= uint64(r.Threads)
+	}
+
+	a.memUsedMin -= r.MinMemory
+	a.memUsedMax -= r.MaxMemory
+}
+
+func canHandleRequest(needRes Resources, spt abi.RegisteredProof, wid WorkerID, res storiface.WorkerResources, active *activeResources) bool {
 
 	// TODO: dedupe needRes.BaseMinMemory per task type (don't add if that task is already running)
-	minNeedMem := res.MemReserved + w.memUsedMin + needRes.MinMemory + needRes.BaseMinMemory
+	minNeedMem := res.MemReserved + active.memUsedMin + needRes.MinMemory + needRes.BaseMinMemory
 	if minNeedMem > res.MemPhysical {
 		log.Debugf("sched: not scheduling on worker %d; not enough physical memory - need: %dM, have %dM", wid, minNeedMem/mib, res.MemPhysical/mib)
-		return false, nil
+		return false
 	}
 
-	maxNeedMem := res.MemReserved + w.memUsedMax + needRes.MaxMemory + needRes.BaseMinMemory
-	if sh.spt == abi.RegisteredProof_StackedDRG32GiBSeal {
+	maxNeedMem := res.MemReserved + active.memUsedMax + needRes.MaxMemory + needRes.BaseMinMemory
+	if spt == abi.RegisteredProof_StackedDRG32GiBSeal {
 		maxNeedMem += MaxCachingOverhead
 	}
 	if maxNeedMem > res.MemSwap+res.MemPhysical {
 		log.Debugf("sched: not scheduling on worker %d; not enough virtual memory - need: %dM, have %dM", wid, maxNeedMem/mib, (res.MemSwap+res.MemPhysical)/mib)
-		return false, nil
+		return false
 	}
 
 	if needRes.MultiThread() {
-		if w.cpuUse > 0 {
-			log.Debugf("sched: not scheduling on worker %d; multicore process needs %d threads, %d in use, target %d", wid, res.CPUs, w.cpuUse, res.CPUs)
-			return false, nil
+		if active.cpuUse > 0 {
+			log.Debugf("sched: not scheduling on worker %d; multicore process needs %d threads, %d in use, target %d", wid, res.CPUs, active.cpuUse, res.CPUs)
+			return false
 		}
 	}
 
 	if len(res.GPUs) > 0 && needRes.CanGPU {
-		if w.gpuUsed {
+		if active.gpuUsed {
 			log.Debugf("sched: not scheduling on worker %d; GPU in use", wid)
-			return false, nil
+			return false
 		}
 	}
 
-	return true, nil
+	return true
 }
 
 func (sh *scheduler) schedNewWorker(w *workerHandle) {
diff --git a/selector_alloc.go b/selector_alloc.go
new file mode 100644
index 000000000..1ceab0ecb
--- /dev/null
+++ b/selector_alloc.go
@@ -0,0 +1,59 @@
+package sectorstorage
+
+import (
+	"context"
+
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/sector-storage/sealtasks"
+	"github.com/filecoin-project/sector-storage/stores"
+)
+
+type allocSelector struct {
+	best []stores.StorageInfo
+}
+
+func newAllocSelector(ctx context.Context, index stores.SectorIndex, alloc stores.SectorFileType) (*allocSelector, error) {
+	best, err := index.StorageBestAlloc(ctx, alloc, true)
+	if err != nil {
+		return nil, err
+	}
+
+	return &allocSelector{
+		best: best,
+	}, nil
+}
+
+func (s *allocSelector) Ok(ctx context.Context, task sealtasks.TaskType, whnd *workerHandle) (bool, error) {
+	tasks, err := whnd.w.TaskTypes(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting supported worker task types: %w", err)
+	}
+	if _, supported := tasks[task]; !supported {
+		return false, nil
+	}
+
+	paths, err := whnd.w.Paths(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting worker paths: %w", err)
+	}
+
+	have := map[stores.ID]struct{}{}
+	for _, path := range paths {
+		have[path.ID] = struct{}{}
+	}
+
+	for _, info := range s.best {
+		if _, ok := have[info.ID]; ok {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func (s *allocSelector) Cmp(ctx context.Context, task sealtasks.TaskType, a, b *workerHandle) (bool, error) {
+	return a.info.Hostname > b.info.Hostname, nil // TODO: Better strategy
+}
+
+var _ WorkerSelector = &allocSelector{}
diff --git a/selector_existing.go b/selector_existing.go
new file mode 100644
index 000000000..eccdefbf2
--- /dev/null
+++ b/selector_existing.go
@@ -0,0 +1,60 @@
+package sectorstorage
+
+import (
+	"context"
+
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/sector-storage/sealtasks"
+	"github.com/filecoin-project/sector-storage/stores"
+	"github.com/filecoin-project/specs-actors/actors/abi"
+)
+
+type existingSelector struct {
+	best []stores.StorageInfo
+}
+
+func newExistingSelector(ctx context.Context, index stores.SectorIndex, sector abi.SectorID, alloc stores.SectorFileType, allowFetch bool) (*existingSelector, error) {
+	best, err := index.StorageFindSector(ctx, sector, alloc, allowFetch)
+	if err != nil {
+		return nil, err
+	}
+
+	return &existingSelector{
+		best: best,
+	}, nil
+}
+
+func (s *existingSelector) Ok(ctx context.Context, task sealtasks.TaskType, whnd *workerHandle) (bool, error) {
+	tasks, err := whnd.w.TaskTypes(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting supported worker task types: %w", err)
+	}
+	if _, supported := tasks[task]; !supported {
+		return false, nil
+	}
+
+	paths, err := whnd.w.Paths(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting worker paths: %w", err)
+	}
+
+	have := map[stores.ID]struct{}{}
+	for _, path := range paths {
+		have[path.ID] = struct{}{}
+	}
+
+	for _, info := range s.best {
+		if _, ok := have[info.ID]; ok {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func (s *existingSelector) Cmp(ctx context.Context, task sealtasks.TaskType, a, b *workerHandle) (bool, error) {
+	return a.info.Hostname > b.info.Hostname, nil // TODO: Better strategy
+}
+
+var _ WorkerSelector = &existingSelector{}
diff --git a/selector_task.go b/selector_task.go
new file mode 100644
index 000000000..f1f4b7770
--- /dev/null
+++ b/selector_task.go
@@ -0,0 +1,46 @@
+package sectorstorage
+
+import (
+	"context"
+
+	"golang.org/x/xerrors"
+
+	"github.com/filecoin-project/sector-storage/sealtasks"
+	"github.com/filecoin-project/sector-storage/stores"
+)
+
+type taskSelector struct {
+	best []stores.StorageInfo
+}
+
+func newTaskSelector() *taskSelector {
+	return &taskSelector{}
+}
+
+func (s *taskSelector) Ok(ctx context.Context, task sealtasks.TaskType, whnd *workerHandle) (bool, error) {
+	tasks, err := whnd.w.TaskTypes(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting supported worker task types: %w", err)
+	}
+	_, supported := tasks[task]
+
+	return supported, nil
+}
+
+func (s *taskSelector) Cmp(ctx context.Context, task sealtasks.TaskType, a, b *workerHandle) (bool, error) {
+	atasks, err := a.w.TaskTypes(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting supported worker task types: %w", err)
+	}
+	btasks, err := b.w.TaskTypes(ctx)
+	if err != nil {
+		return false, xerrors.Errorf("getting supported worker task types: %w", err)
+	}
+	if len(atasks) != len(btasks) {
+		return len(atasks) < len(btasks), nil // prefer workers which can do less
+	}
+
+	return a.info.Hostname > a.info.Hostname, nil // TODO: Better fallback strategy
+}
+
+var _ WorkerSelector = &allocSelector{}
diff --git a/stats.go b/stats.go
index 84e6c5bb3..dbbee07f3 100644
--- a/stats.go
+++ b/stats.go
@@ -11,10 +11,10 @@ func (m *Manager) WorkerStats() map[uint64]storiface.WorkerStats {
 	for id, handle := range m.sched.workers {
 		out[uint64(id)] = storiface.WorkerStats{
 			Info:       handle.info,
-			MemUsedMin: handle.memUsedMin,
-			MemUsedMax: handle.memUsedMax,
-			GpuUsed:    handle.gpuUsed,
-			CpuUse:     handle.cpuUse,
+			MemUsedMin: handle.active.memUsedMin,
+			MemUsedMax: handle.active.memUsedMax,
+			GpuUsed:    handle.active.gpuUsed,
+			CpuUse:     handle.active.cpuUse,
 		}
 	}