diff --git a/etcdctl/ctlv3/command/migrate_command.go b/etcdctl/ctlv3/command/migrate_command.go
index ea17476d9942..634ebb944882 100644
--- a/etcdctl/ctlv3/command/migrate_command.go
+++ b/etcdctl/ctlv3/command/migrate_command.go
@@ -106,7 +106,7 @@ func prepareBackend() backend.Backend {
 	dbpath := filepath.Join(migrateDatadir, "member", "snap", "db")
 	go func() {
 		defer close(bch)
-		be = backend.New(dbpath, time.Second, 10000)
+		be = backend.NewDefaultBackend(dbpath)
 
 	}()
 	select {
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 7a272a0f74fe..63e751ea48a0 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -270,7 +270,7 @@ func NewServer(cfg *ServerConfig) (srv *EtcdServer, err error) {
 	var be backend.Backend
 	beOpened := make(chan struct{})
 	go func() {
-		be = backend.NewDefaultBackend(bepath)
+		be = newBackend(bepath, cfg.QuotaBackendBytes)
 		beOpened <- struct{}{}
 	}()
 
@@ -809,7 +809,7 @@ func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) {
 		plog.Panicf("rename snapshot file error: %v", err)
 	}
 
-	newbe := backend.NewDefaultBackend(fn)
+	newbe := newBackend(fn, s.Cfg.QuotaBackendBytes)
 
 	// always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases.
 	// If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers.
@@ -1653,3 +1653,13 @@ func (s *EtcdServer) goAttach(f func()) {
 		f()
 	}()
 }
+
+func newBackend(path string, quotaBytes int64) backend.Backend {
+	bcfg := backend.DefaultBackendConfig()
+	bcfg.Path = path
+	if quotaBytes > 0 && quotaBytes != DefaultQuotaBytes {
+		// permit 10% excess over quota for disarm
+		bcfg.MmapSize = uint64(quotaBytes + quotaBytes/10)
+	}
+	return backend.New(bcfg)
+}
diff --git a/lease/lessor_test.go b/lease/lessor_test.go
index d417c15f771a..39d9eea45c89 100644
--- a/lease/lessor_test.go
+++ b/lease/lessor_test.go
@@ -390,6 +390,7 @@ func NewTestBackend(t *testing.T) (string, backend.Backend) {
 	if err != nil {
 		t.Fatalf("failed to create tmpdir (%v)", err)
 	}
-
-	return tmpPath, backend.New(filepath.Join(tmpPath, "be"), time.Second, 10000)
+	bcfg := backend.DefaultBackendConfig()
+	bcfg.Path = filepath.Join(tmpPath, "be")
+	return tmpPath, backend.New(bcfg)
 }
diff --git a/mvcc/backend/backend.go b/mvcc/backend/backend.go
index 56a1b69e1261..0a559295ceed 100644
--- a/mvcc/backend/backend.go
+++ b/mvcc/backend/backend.go
@@ -35,10 +35,10 @@ var (
 
 	defragLimit = 10000
 
-	// InitialMmapSize is the initial size of the mmapped region. Setting this larger than
+	// initialMmapSize is the initial size of the mmapped region. Setting this larger than
 	// the potential max db size can prevent writer from blocking reader.
 	// This only works for linux.
-	InitialMmapSize = int64(10 * 1024 * 1024 * 1024)
+	initialMmapSize = uint64(10 * 1024 * 1024 * 1024)
 
 	plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "mvcc/backend")
 )
@@ -96,18 +96,45 @@ type backend struct {
 	donec chan struct{}
 }
 
-func New(path string, d time.Duration, limit int) Backend {
-	return newBackend(path, d, limit)
+type BackendConfig struct {
+	// Path is the file path to the backend file.
+	Path string
+	// BatchInterval is the maximum time before flushing the BatchTx.
+	BatchInterval time.Duration
+	// BatchLimit is the maximum puts before flushing the BatchTx.
+	BatchLimit int
+	// MmapSize is the number of bytes to mmap for the backend.
+	MmapSize uint64
+}
+
+func DefaultBackendConfig() BackendConfig {
+	return BackendConfig{
+		BatchInterval: defaultBatchInterval,
+		BatchLimit:    defaultBatchLimit,
+		MmapSize:      initialMmapSize,
+	}
+}
+
+func New(bcfg BackendConfig) Backend {
+	return newBackend(bcfg)
 }
 
 func NewDefaultBackend(path string) Backend {
-	return newBackend(path, defaultBatchInterval, defaultBatchLimit)
+	bcfg := DefaultBackendConfig()
+	bcfg.Path = path
+	return newBackend(bcfg)
 }
 
-func newBackend(path string, d time.Duration, limit int) *backend {
-	db, err := bolt.Open(path, 0600, boltOpenOptions)
+func newBackend(bcfg BackendConfig) *backend {
+	bopts := &bolt.Options{}
+	if boltOpenOptions != nil {
+		*bopts = *boltOpenOptions
+	}
+	bopts.InitialMmapSize = int(bcfg.MmapSize)
+
+	db, err := bolt.Open(bcfg.Path, 0600, bopts)
 	if err != nil {
-		plog.Panicf("cannot open database at %s (%v)", path, err)
+		plog.Panicf("cannot open database at %s (%v)", bcfg.Path, err)
 	}
 
 	// In future, may want to make buffering optional for low-concurrency systems
@@ -115,8 +142,8 @@ func newBackend(path string, d time.Duration, limit int) *backend {
 	b := &backend{
 		db: db,
 
-		batchInterval: d,
-		batchLimit:    limit,
+		batchInterval: bcfg.BatchInterval,
+		batchLimit:    bcfg.BatchLimit,
 
 		readTx: &readTx{buf: txReadBuffer{
 			txBuffer: txBuffer{make(map[string]*bucketBuffer)}},
@@ -358,7 +385,9 @@ func NewTmpBackend(batchInterval time.Duration, batchLimit int) (*backend, strin
 		plog.Fatal(err)
 	}
 	tmpPath := filepath.Join(dir, "database")
-	return newBackend(tmpPath, batchInterval, batchLimit), tmpPath
+	bcfg := DefaultBackendConfig()
+	bcfg.Path, bcfg.BatchInterval, bcfg.BatchLimit = tmpPath, batchInterval, batchLimit
+	return newBackend(bcfg), tmpPath
 }
 
 func NewDefaultTmpBackend() (*backend, string) {
diff --git a/mvcc/backend/backend_bench_test.go b/mvcc/backend/backend_bench_test.go
index 6d2570e67b03..30b47516f155 100644
--- a/mvcc/backend/backend_bench_test.go
+++ b/mvcc/backend/backend_bench_test.go
@@ -22,9 +22,9 @@ import (
 )
 
 func BenchmarkBackendPut(b *testing.B) {
-	backend := New("test", 100*time.Millisecond, 10000)
+	backend, tmppath := NewTmpBackend(100*time.Millisecond, 10000)
 	defer backend.Close()
-	defer os.Remove("test")
+	defer os.Remove(tmppath)
 
 	// prepare keys
 	keys := make([][]byte, b.N)
diff --git a/mvcc/backend/backend_test.go b/mvcc/backend/backend_test.go
index 68d0b19599e8..af898b5ad3af 100644
--- a/mvcc/backend/backend_test.go
+++ b/mvcc/backend/backend_test.go
@@ -69,7 +69,9 @@ func TestBackendSnapshot(t *testing.T) {
 	f.Close()
 
 	// bootstrap new backend from the snapshot
-	nb := New(f.Name(), time.Hour, 10000)
+	bcfg := DefaultBackendConfig()
+	bcfg.Path, bcfg.BatchInterval, bcfg.BatchLimit = f.Name(), time.Hour, 10000
+	nb := New(bcfg)
 	defer cleanup(nb, f.Name())
 
 	newTx := b.BatchTx()
diff --git a/mvcc/backend/boltoption_linux.go b/mvcc/backend/boltoption_linux.go
index 4ee9b05a77cb..c65b477a0d95 100644
--- a/mvcc/backend/boltoption_linux.go
+++ b/mvcc/backend/boltoption_linux.go
@@ -27,6 +27,5 @@ import (
 // (https://github.com/torvalds/linux/releases/tag/v2.6.23), mmap might
 // silently ignore this flag. Please update your kernel to prevent this.
 var boltOpenOptions = &bolt.Options{
-	MmapFlags:       syscall.MAP_POPULATE,
-	InitialMmapSize: int(InitialMmapSize),
+	MmapFlags: syscall.MAP_POPULATE,
 }