diff --git a/build/params.go b/build/params.go
index 0c4908b74..2545bd33a 100644
--- a/build/params.go
+++ b/build/params.go
@@ -125,5 +125,5 @@ func init() {
 const BadBlockCacheSize = 8192
 
 // assuming 4000 blocks per round, this lets us not lose any messages across a
-// 10 block reorg. 
+// 10 block reorg.
 const BlsSignatureCacheSize = 40000
diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index 0d951f1fe..c7866c81e 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -75,7 +75,7 @@ func (m mybs) Get(c cid.Cid) (block.Block, error) {
 
 func NewGenerator() (*ChainGen, error) {
 	mr := repo.NewMemory(nil)
-	lr, err := mr.Lock(repo.RepoStorageMiner)
+	lr, err := mr.Lock(repo.StorageMiner)
 	if err != nil {
 		return nil, xerrors.Errorf("taking mem-repo lock failed: %w", err)
 	}
diff --git a/cmd/lotus-storage-miner/init.go b/cmd/lotus-storage-miner/init.go
index 5943d6dac..3cddbf866 100644
--- a/cmd/lotus-storage-miner/init.go
+++ b/cmd/lotus-storage-miner/init.go
@@ -101,7 +101,7 @@ var initCmd = &cli.Command{
 
 		log.Info("Initializing repo")
 
-		if err := r.Init(repo.RepoStorageMiner); err != nil {
+		if err := r.Init(repo.StorageMiner); err != nil {
 			return err
 		}
 
@@ -122,7 +122,7 @@ var initCmd = &cli.Command{
 }
 
 func storageMinerInit(ctx context.Context, cctx *cli.Context, api api.FullNode, r repo.Repo) error {
-	lr, err := r.Lock(repo.RepoStorageMiner)
+	lr, err := r.Lock(repo.StorageMiner)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/lotus-storage-miner/run.go b/cmd/lotus-storage-miner/run.go
index c8a10baac..7f978806e 100644
--- a/cmd/lotus-storage-miner/run.go
+++ b/cmd/lotus-storage-miner/run.go
@@ -17,9 +17,7 @@ import (
 	lcli "github.com/filecoin-project/lotus/cli"
 	"github.com/filecoin-project/lotus/lib/auth"
 	"github.com/filecoin-project/lotus/lib/jsonrpc"
-	"github.com/filecoin-project/lotus/lib/sectorbuilder"
 	"github.com/filecoin-project/lotus/node"
-	"github.com/filecoin-project/lotus/node/modules"
 	"github.com/filecoin-project/lotus/node/repo"
 )
 
@@ -84,7 +82,6 @@ var runCmd = &cli.Command{
 				}
 				return lr.SetAPIEndpoint(apima)
 			}),
-			node.Override(new(*sectorbuilder.Config), modules.SectorBuilderConfig(storageRepoPath, 5)), // TODO: grab worker count from config
 			node.Override(new(api.FullNode), nodeApi),
 		)
 		if err != nil {
diff --git a/cmd/lotus/daemon.go b/cmd/lotus/daemon.go
index 4921f3930..5a978a105 100644
--- a/cmd/lotus/daemon.go
+++ b/cmd/lotus/daemon.go
@@ -54,7 +54,7 @@ var DaemonCmd = &cli.Command{
 			return err
 		}
 
-		if err := r.Init(repo.RepoFullNode); err != nil && err != repo.ErrRepoExists {
+		if err := r.Init(repo.FullNode); err != nil && err != repo.ErrRepoExists {
 			return err
 		}
 
diff --git a/lib/sectorbuilder/sectorbuilder.go b/lib/sectorbuilder/sectorbuilder.go
index 35f37ac2d..716cefe15 100644
--- a/lib/sectorbuilder/sectorbuilder.go
+++ b/lib/sectorbuilder/sectorbuilder.go
@@ -127,7 +127,7 @@ func New(cfg *Config, ds dtypes.MetadataDS) (*SectorBuilder, error) {
 	return sb, nil
 }
 
-func (sb *SectorBuilder) rlimit() func() {
+func (sb *SectorBuilder) RateLimit() func() {
 	if cap(sb.rateLimit) == len(sb.rateLimit) {
 		log.Warn("rate-limiting sectorbuilder call")
 	}
@@ -173,7 +173,7 @@ func (sb *SectorBuilder) AddPiece(pieceSize uint64, sectorId uint64, file io.Rea
 		return PublicPieceInfo{}, err
 	}
 
-	ret := sb.rlimit()
+	ret := sb.RateLimit()
 	defer ret()
 
 	stagedFile, err := sb.stagedSectorFile(sectorId)
@@ -202,14 +202,14 @@ func (sb *SectorBuilder) AddPiece(pieceSize uint64, sectorId uint64, file io.Rea
 
 // TODO: should *really really* return an io.ReadCloser
 func (sb *SectorBuilder) ReadPieceFromSealedSector(pieceKey string) ([]byte, error) {
-	ret := sb.rlimit()
+	ret := sb.RateLimit()
 	defer ret()
 
 	return sectorbuilder.ReadPieceFromSealedSector(sb.handle, pieceKey)
 }
 
 func (sb *SectorBuilder) SealPreCommit(sectorID uint64, ticket SealTicket, pieces []PublicPieceInfo) (RawSealPreCommitOutput, error) {
-	ret := sb.rlimit()
+	ret := sb.RateLimit()
 	defer ret()
 
 	cacheDir, err := sb.sectorCacheDir(sectorID)
@@ -252,7 +252,7 @@ func (sb *SectorBuilder) SealPreCommit(sectorID uint64, ticket SealTicket, piece
 }
 
 func (sb *SectorBuilder) SealCommit(sectorID uint64, ticket SealTicket, seed SealSeed, pieces []PublicPieceInfo, pieceKeys []string, rspco RawSealPreCommitOutput) (proof []byte, err error) {
-	ret := sb.rlimit()
+	ret := sb.RateLimit()
 	defer ret()
 
 	cacheDir, err := sb.sectorCacheDir(sectorID)
diff --git a/lib/sectorbuilder/sectorbuilder_test.go b/lib/sectorbuilder/sectorbuilder_test.go
index bb965c2bb..a5e394b36 100644
--- a/lib/sectorbuilder/sectorbuilder_test.go
+++ b/lib/sectorbuilder/sectorbuilder_test.go
@@ -1,16 +1,15 @@
 package sectorbuilder_test
 
 import (
+	"github.com/ipfs/go-datastore"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"io"
 	"io/ioutil"
 	"math/rand"
 	"os"
 	"testing"
 
-	"github.com/ipfs/go-datastore"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
 	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/lib/sectorbuilder"
 )
@@ -20,6 +19,7 @@ const sectorSize = 1024
 func TestSealAndVerify(t *testing.T) {
 	//t.Skip("this is slow")
 	os.Setenv("BELLMAN_NO_GPU", "1")
+	os.Setenv("RUST_LOG", "info")
 
 	build.SectorSizes = []uint64{sectorSize}
 
diff --git a/node/builder.go b/node/builder.go
index 12a2f7e79..1bf6881fc 100644
--- a/node/builder.go
+++ b/node/builder.go
@@ -181,7 +181,7 @@ func Online() Option {
 
 		// Full node
 
-		ApplyIf(isType(repo.RepoFullNode),
+		ApplyIf(isType(repo.FullNode),
 			// TODO: Fix offline mode
 
 			Override(new(dtypes.BootstrapPeers), modules.BuiltinBootstrap),
@@ -235,7 +235,7 @@ func Online() Option {
 		),
 
 		// Storage miner
-		ApplyIf(func(s *Settings) bool { return s.nodeType == repo.RepoStorageMiner },
+		ApplyIf(func(s *Settings) bool { return s.nodeType == repo.StorageMiner },
 			Override(new(*sectorbuilder.SectorBuilder), modules.SectorBuilder),
 			Override(new(*sectorblocks.SectorBlocks), sectorblocks.NewSectorBlocks),
 			Override(new(storage.TicketFn), modules.SealTicketGen),
@@ -266,7 +266,7 @@ func StorageMiner(out *api.StorageMiner) Option {
 		),
 
 		func(s *Settings) error {
-			s.nodeType = repo.RepoStorageMiner
+			s.nodeType = repo.StorageMiner
 			return nil
 		},
 
@@ -294,30 +294,34 @@ func ConfigCommon(cfg *config.Common) Option {
 	)
 }
 
-func ConfigFullNode(cfg *config.FullNode) Option {
-	//ApplyIf(func(s *Settings) bool { return s.nodeType == repo.RepoFullNode }),
+func ConfigFullNode(c interface{}) Option {
+	cfg, ok := c.(*config.FullNode)
+	if !ok {
+		return Error(xerrors.Errorf("invalid config from repo, got: %T", c))
+	}
+
 	return Options(
 		ConfigCommon(&cfg.Common),
 		Override(HeadMetricsKey, metrics.SendHeadNotifs(cfg.Metrics.Nickname)),
 	)
 }
 
-func configFull(c interface{}) Option {
-	cfg, ok := c.(*config.FullNode)
-	if !ok {
-		return Error(xerrors.Errorf("invalid config from repo, got: %T", c))
-	}
-
-	return ConfigFullNode(cfg)
-}
-
-func configMiner(c interface{}) Option {
+func ConfigStorageMiner(c interface{}, lr repo.LockedRepo) Option {
 	cfg, ok := c.(*config.StorageMiner)
 	if !ok {
 		return Error(xerrors.Errorf("invalid config from repo, got: %T", c))
 	}
 
-	return ConfigCommon(&cfg.Common)
+	path := cfg.SectorBuilder.Path
+	if path == "" {
+		path = lr.Path()
+	}
+
+	return Options(
+		ConfigCommon(&cfg.Common),
+
+		Override(new(*sectorbuilder.Config), modules.SectorBuilderConfig(path, cfg.SectorBuilder.WorkerCount)),
+	)
 }
 
 func Repo(r repo.Repo) Option {
@@ -334,8 +338,8 @@ func Repo(r repo.Repo) Option {
 		return Options(
 			Override(new(repo.LockedRepo), modules.LockedRepo(lr)), // module handles closing
 
-			ApplyIf(isType(repo.RepoFullNode), configFull(c)),
-			ApplyIf(isType(repo.RepoStorageMiner), configMiner(c)),
+			ApplyIf(isType(repo.FullNode), ConfigFullNode(c)),
+			ApplyIf(isType(repo.StorageMiner), ConfigStorageMiner(c, lr)),
 
 			Override(new(dtypes.MetadataDS), modules.Datastore),
 			Override(new(dtypes.ChainBlockstore), modules.ChainBlockstore),
@@ -371,7 +375,7 @@ func New(ctx context.Context, opts ...Option) (StopFunc, error) {
 	settings := Settings{
 		modules:  map[interface{}]fx.Option{},
 		invokes:  make([]fx.Option, _nInvokes),
-		nodeType: repo.RepoFullNode,
+		nodeType: repo.FullNode,
 	}
 
 	// apply module options in the right order
diff --git a/node/config/def.go b/node/config/def.go
index 93a876656..928ea1d6d 100644
--- a/node/config/def.go
+++ b/node/config/def.go
@@ -17,9 +17,13 @@ type FullNode struct {
 	Metrics Metrics
 }
 
+// // Common
+
 // StorageMiner is a storage miner config
 type StorageMiner struct {
 	Common
+
+	SectorBuilder SectorBuilder
 }
 
 // API contains configs for API endpoint
@@ -34,10 +38,19 @@ type Libp2p struct {
 	BootstrapPeers  []string
 }
 
+// // Full Node
+
 type Metrics struct {
 	Nickname string
 }
 
+// // Storage Miner
+
+type SectorBuilder struct {
+	Path        string
+	WorkerCount uint
+}
+
 func defCommon() Common {
 	return Common{
 		API: API{
@@ -64,6 +77,10 @@ func DefaultFullNode() *FullNode {
 func DefaultStorageMiner() *StorageMiner {
 	return &StorageMiner{
 		Common: defCommon(),
+
+		SectorBuilder: SectorBuilder{
+			WorkerCount: 5,
+		},
 	}
 }
 
diff --git a/node/node_test.go b/node/node_test.go
index 1d8c20b03..a1ee38c75 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -4,9 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
-	"io/ioutil"
 	"net/http/httptest"
-	"os"
 	"testing"
 
 	"github.com/libp2p/go-libp2p-core/crypto"
@@ -23,7 +21,6 @@ import (
 	"github.com/filecoin-project/lotus/chain/address"
 	"github.com/filecoin-project/lotus/chain/types"
 	"github.com/filecoin-project/lotus/lib/jsonrpc"
-	"github.com/filecoin-project/lotus/lib/sectorbuilder"
 	"github.com/filecoin-project/lotus/miner"
 	"github.com/filecoin-project/lotus/node"
 	"github.com/filecoin-project/lotus/node/modules"
@@ -34,7 +31,7 @@ import (
 func testStorageNode(ctx context.Context, t *testing.T, waddr address.Address, act address.Address, pk crypto.PrivKey, tnd test.TestNode, mn mocknet.Mocknet) test.TestStorageNode {
 	r := repo.NewMemory(nil)
 
-	lr, err := r.Lock(repo.RepoStorageMiner)
+	lr, err := r.Lock(repo.StorageMiner)
 	require.NoError(t, err)
 
 	ks, err := lr.KeyStore()
@@ -77,10 +74,6 @@ func testStorageNode(ctx context.Context, t *testing.T, waddr address.Address, a
 	require.NoError(t, err)
 
 	// start node
-
-	secbpath, err := ioutil.TempDir(os.TempDir(), "lotust-stortest-sb-")
-	require.NoError(t, err)
-
 	var minerapi api.StorageMiner
 
 	// TODO: use stop
@@ -92,7 +85,6 @@ func testStorageNode(ctx context.Context, t *testing.T, waddr address.Address, a
 
 		node.MockHost(mn),
 
-		node.Override(new(*sectorbuilder.Config), modules.SectorBuilderConfig(secbpath, 2)),
 		node.Override(new(api.FullNode), tnd),
 	)
 	require.NoError(t, err)
diff --git a/node/repo/fsrepo.go b/node/repo/fsrepo.go
index 0a81e6513..cce67ba8a 100644
--- a/node/repo/fsrepo.go
+++ b/node/repo/fsrepo.go
@@ -37,16 +37,16 @@ const (
 type RepoType int
 
 const (
-	_                     = iota // Default is invalid
-	RepoFullNode RepoType = iota
-	RepoStorageMiner
+	_                 = iota // Default is invalid
+	FullNode RepoType = iota
+	StorageMiner
 )
 
 func defConfForType(t RepoType) interface{} {
 	switch t {
-	case RepoFullNode:
+	case FullNode:
 		return config.DefaultFullNode()
-	case RepoStorageMiner:
+	case StorageMiner:
 		return config.DefaultStorageMiner()
 	default:
 		panic(fmt.Sprintf("unknown RepoType(%d)", int(t)))
diff --git a/node/repo/fsrepo_test.go b/node/repo/fsrepo_test.go
index de55eb351..bd03cc084 100644
--- a/node/repo/fsrepo_test.go
+++ b/node/repo/fsrepo_test.go
@@ -17,7 +17,7 @@ func genFsRepo(t *testing.T) (*FsRepo, func()) {
 		t.Fatal(err)
 	}
 
-	err = repo.Init(RepoFullNode)
+	err = repo.Init(FullNode)
 	if err != ErrRepoExists && err != nil {
 		t.Fatal(err)
 	}
diff --git a/node/repo/memrepo.go b/node/repo/memrepo.go
index 00f6de424..6cc54ddb9 100644
--- a/node/repo/memrepo.go
+++ b/node/repo/memrepo.go
@@ -1,6 +1,8 @@
 package repo
 
 import (
+	"io/ioutil"
+	"os"
 	"sync"
 
 	"github.com/ipfs/go-datastore"
@@ -32,11 +34,20 @@ type lockedMemRepo struct {
 	t   RepoType
 	sync.RWMutex
 
-	token *byte
+	tempDir string
+	token   *byte
 }
 
 func (lmem *lockedMemRepo) Path() string {
-	return ""
+	t, err := ioutil.TempDir(os.TempDir(), "lotus-memrepo-temp-")
+	if err != nil {
+		panic(err) // only used in tests, probably fine
+	}
+
+	lmem.Lock()
+	lmem.tempDir = t
+	lmem.Unlock()
+	return t
 }
 
 var _ Repo = &MemRepo{}
@@ -127,6 +138,13 @@ func (lmem *lockedMemRepo) Close() error {
 		return ErrClosedRepo
 	}
 
+	if lmem.tempDir != "" {
+		if err := os.RemoveAll(lmem.tempDir); err != nil {
+			return err
+		}
+		lmem.tempDir = ""
+	}
+
 	lmem.mem.token = nil
 	lmem.mem.api.Lock()
 	lmem.mem.api.ma = nil
diff --git a/node/repo/repo_test.go b/node/repo/repo_test.go
index d9cdc5dc5..9c43e8f4b 100644
--- a/node/repo/repo_test.go
+++ b/node/repo/repo_test.go
@@ -18,12 +18,12 @@ func basicTest(t *testing.T, repo Repo) {
 	}
 	assert.Nil(t, apima, "with no api endpoint, return should be nil")
 
-	lrepo, err := repo.Lock(RepoFullNode)
+	lrepo, err := repo.Lock(FullNode)
 	assert.NoError(t, err, "should be able to lock once")
 	assert.NotNil(t, lrepo, "locked repo shouldn't be nil")
 
 	{
-		lrepo2, err := repo.Lock(RepoFullNode)
+		lrepo2, err := repo.Lock(FullNode)
 		if assert.Error(t, err) {
 			assert.Equal(t, ErrRepoAlreadyLocked, err)
 		}
@@ -33,7 +33,7 @@ func basicTest(t *testing.T, repo Repo) {
 	err = lrepo.Close()
 	assert.NoError(t, err, "should be able to unlock")
 
-	lrepo, err = repo.Lock(RepoFullNode)
+	lrepo, err = repo.Lock(FullNode)
 	assert.NoError(t, err, "should be able to relock")
 	assert.NotNil(t, lrepo, "locked repo shouldn't be nil")
 
@@ -64,7 +64,7 @@ func basicTest(t *testing.T, repo Repo) {
 	k1 := types.KeyInfo{Type: "foo"}
 	k2 := types.KeyInfo{Type: "bar"}
 
-	lrepo, err = repo.Lock(RepoFullNode)
+	lrepo, err = repo.Lock(FullNode)
 	assert.NoError(t, err, "should be able to relock")
 	assert.NotNil(t, lrepo, "locked repo shouldn't be nil")
 
diff --git a/storage/garbage.go b/storage/garbage.go
index f61ff50cc..ab41d6ff0 100644
--- a/storage/garbage.go
+++ b/storage/garbage.go
@@ -23,7 +23,10 @@ func (m *Miner) storeGarbage(ctx context.Context, sectorID uint64, existingPiece
 
 	deals := make([]actors.StorageDeal, len(sizes))
 	for i, size := range sizes {
+		release := m.sb.RateLimit()
 		commP, err := sectorbuilder.GeneratePieceCommitment(io.LimitReader(rand.New(rand.NewSource(42)), int64(size)), size)
+		release()
+
 		if err != nil {
 			return nil, err
 		}