diff --git a/block.go b/block.go
index e11a3fe46..aa70017d9 100644
--- a/block.go
+++ b/block.go
@@ -1,7 +1,6 @@
 package tsdb
 
 import (
-	"fmt"
 	"io"
 	"sort"
 	"unsafe"
@@ -15,69 +14,11 @@ const (
 // Block handles reads against a block of time series data within a time window.
 type Block interface{}
 
-type persistedSeries struct {
-	size    int
-	dataref []byte
-	data    *[maxMapSize]byte
-}
-
 const (
 	flagNone = 0
 	flagStd  = 1
 )
 
-const (
-	metaSize        = int(unsafe.Sizeof(meta{}))
-	seriesStatsSize = int(unsafe.Sizeof(blockStats{}))
-)
-
-type meta struct {
-	magic uint32
-	flag  byte
-	_     [7]byte // padding/reserved
-}
-
-type blockStats struct {
-	chunks  uint32
-	samples uint64
-	_       [4]byte // padding/reserved
-}
-
-func (s *persistedSeries) meta() *meta {
-	return (*meta)(unsafe.Pointer(&s.data[0]))
-}
-
-func (s *persistedSeries) stats() *blockStats {
-	// The stats start right behind the block meta data.
-	return (*blockStats)(unsafe.Pointer(&s.data[metaSize]))
-}
-
-// seriesAt returns the series stored at offset as a skiplist and the chunks
-// it points to as a byte slice.
-func (s *persistedSeries) seriesAt(offset int) (skiplist, []byte, error) {
-	offset += metaSize
-	offset += seriesStatsSize
-
-	switch b := s.data[offset]; b {
-	case flagStd:
-	default:
-		return nil, nil, fmt.Errorf("invalid flag: %x", b)
-	}
-	offset++
-
-	var (
-		slLen  = *(*uint16)(unsafe.Pointer(&s.data[offset]))
-		slSize = int(slLen) / int(unsafe.Sizeof(skiplistPair{}))
-		sl     = ((*[maxAllocSize]skiplistPair)(unsafe.Pointer(&s.data[offset+2])))[:slSize]
-	)
-	offset += 3
-
-	chunksLen := *(*uint32)(unsafe.Pointer(&s.data[offset]))
-	chunks := ((*[maxAllocSize]byte)(unsafe.Pointer(&s.data[offset])))[:chunksLen]
-
-	return simpleSkiplist(sl), chunks, nil
-}
-
 // A skiplist maps offsets to values. The values found in the data at an
 // offset are strictly greater than the indexed value.
 type skiplist interface {
diff --git a/db.go b/db.go
index 54e4632bd..6decbd611 100644
--- a/db.go
+++ b/db.go
@@ -2,6 +2,7 @@
 package tsdb
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -93,6 +94,72 @@ func (db *DB) Querier(start, end int64) Querier {
 	return nil
 }
 
+// Appender adds a batch of samples.
+type Appender interface {
+	// Add adds a sample pair to the appended batch.
+	Add(l Labels, t int64, v float64)
+
+	// Commit submits the collected samples.
+	Commit() error
+}
+
+// Vector is a set of LabelSet associated with one value each.
+// Label sets and values must have equal length.
+type Vector struct {
+	Buckets map[uint16][]Sample
+	reused  int
+}
+
+type Sample struct {
+	Hash   uint64
+	Labels Labels
+	Value  float64
+}
+
+// Reset the vector but keep resources allocated.
+func (v *Vector) Reset() {
+	// Do a full reset every n-th reusage to avoid memory leaks.
+	if v.Buckets == nil || v.reused > 100 {
+		v.Buckets = make(map[uint16][]Sample, 0)
+		return
+	}
+	for x, bkt := range v.Buckets {
+		v.Buckets[x] = bkt[:0]
+	}
+	v.reused++
+}
+
+// Add a sample to the vector.
+func (v *Vector) Add(lset Labels, val float64) {
+	h := lset.Hash()
+	s := uint16(h >> (64 - seriesShardShift))
+
+	v.Buckets[s] = append(v.Buckets[s], Sample{
+		Hash:   h,
+		Labels: lset,
+		Value:  val,
+	})
+}
+
+// func (db *DB) Appender() Appender {
+// 	return &bucketAppender{
+// 		samples: make([]Sample, 1024),
+// 	}
+// }
+
+// type bucketAppender struct {
+// 	db *DB
+// 	// buckets []Sam
+// }
+
+// func (a *bucketAppender) Add(l Labels, t int64, v float64) {
+
+// }
+
+// func (a *bucketAppender) Commit() error {
+// 	// f
+// }
+
 // AppendVector adds values for a list of label sets for the given timestamp
 // in milliseconds.
 func (db *DB) AppendVector(ts int64, v *Vector) error {
@@ -121,59 +188,6 @@ func (db *DB) appendSingle(lset Labels, ts int64, v float64) error {
 	})
 }
 
-// Matcher matches a string.
-type Matcher interface {
-	// Match returns true if the matcher applies to the string value.
-	Match(v string) bool
-}
-
-// Querier provides querying access over time series data of a fixed
-// time range.
-type Querier interface {
-	// Range returns the timestamp range of the Querier.
-	Range() (start, end int64)
-
-	// Iterator returns an interator over the inverted index that
-	// matches the key label by the constraints of Matcher.
-	Iterator(key string, m Matcher) Iterator
-
-	// Labels resolves a label reference into a set of labels.
-	Labels(ref LabelRefs) (Labels, error)
-
-	// Series returns series provided in the index iterator.
-	Series(Iterator) []Series
-
-	// LabelValues returns all potential values for a label name.
-	LabelValues(string) []string
-	// LabelValuesFor returns all potential values for a label name.
-	// under the constraint of another label.
-	LabelValuesFor(string, Label) []string
-
-	// Close releases the resources of the Querier.
-	Close() error
-}
-
-// Series represents a single time series.
-type Series interface {
-	Labels() Labels
-	// Iterator returns a new iterator of the data of the series.
-	Iterator() SeriesIterator
-}
-
-// SeriesIterator iterates over the data of a time series.
-type SeriesIterator interface {
-	// Seek advances the iterator forward to the given timestamp.
-	// If there's no value exactly at ts, it advances to the last value
-	// before ts.
-	Seek(ts int64) bool
-	// Values returns the current timestamp/value pair.
-	Values() (int64, float64)
-	// Next advances the iterator by one.
-	Next() bool
-	// Err returns the current error.
-	Err() error
-}
-
 const sep = '\xff'
 
 // SeriesShard handles reads and writes of time series falling into
@@ -434,40 +448,24 @@ func LabelsFromMap(m map[string]string) Labels {
 	return NewLabels(l...)
 }
 
-// Vector is a set of LabelSet associated with one value each.
-// Label sets and values must have equal length.
-type Vector struct {
-	Buckets map[uint16][]Sample
-	reused  int
-}
+// The MultiError type implements the error interface, and contains the
+// Errors used to construct it.
+type MultiError []error
 
-type Sample struct {
-	Hash   uint64
-	Labels Labels
-	Value  float64
-}
+// Returns a concatenated string of the contained errors
+func (es MultiError) Error() string {
+	var buf bytes.Buffer
 
-// Reset the vector but keep resources allocated.
-func (v *Vector) Reset() {
-	// Do a full reset every n-th reusage to avoid memory leaks.
-	if v.Buckets == nil || v.reused > 100 {
-		v.Buckets = make(map[uint16][]Sample, 0)
-		return
+	if len(es) > 0 {
+		fmt.Fprintf(&buf, "%d errors: ", len(es))
 	}
-	for x, bkt := range v.Buckets {
-		v.Buckets[x] = bkt[:0]
+
+	for i, err := range es {
+		if i != 0 {
+			buf.WriteString("; ")
+		}
+		buf.WriteString(err.Error())
 	}
-	v.reused++
-}
 
-// Add a sample to the vector.
-func (v *Vector) Add(lset Labels, val float64) {
-	h := lset.Hash()
-	s := uint16(h >> (64 - seriesShardShift))
-
-	v.Buckets[s] = append(v.Buckets[s], Sample{
-		Hash:   h,
-		Labels: lset,
-		Value:  val,
-	})
+	return buf.String()
 }
diff --git a/head.go b/head.go
index c14be744b..73db76086 100644
--- a/head.go
+++ b/head.go
@@ -56,6 +56,11 @@ func (h *HeadBlock) append(hash uint64, lset Labels, ts int64, v float64) error
 	return nil
 }
 
+type blockStats struct {
+	chunks  uint32
+	samples uint64
+}
+
 func (h *HeadBlock) stats() *blockStats {
 	return &blockStats{
 		chunks:  uint32(h.index.numSeries()),
diff --git a/querier.go b/querier.go
new file mode 100644
index 000000000..dd5c160fe
--- /dev/null
+++ b/querier.go
@@ -0,0 +1,54 @@
+package tsdb
+
+// Matcher matches a string.
+type Matcher interface {
+	// Match returns true if the matcher applies to the string value.
+	Match(v string) bool
+}
+
+// Querier provides querying access over time series data of a fixed
+// time range.
+type Querier interface {
+	// Range returns the timestamp range of the Querier.
+	Range() (start, end int64)
+
+	// Iterator returns an interator over the inverted index that
+	// matches the key label by the constraints of Matcher.
+	Iterator(key string, m Matcher) Iterator
+
+	// Labels resolves a label reference into a set of labels.
+	Labels(ref LabelRefs) (Labels, error)
+
+	// Series returns series provided in the index iterator.
+	Series(Iterator) []Series
+
+	// LabelValues returns all potential values for a label name.
+	LabelValues(string) []string
+	// LabelValuesFor returns all potential values for a label name.
+	// under the constraint of another label.
+	LabelValuesFor(string, Label) []string
+
+	// Close releases the resources of the Querier.
+	Close() error
+}
+
+// Series represents a single time series.
+type Series interface {
+	Labels() Labels
+	// Iterator returns a new iterator of the data of the series.
+	Iterator() SeriesIterator
+}
+
+// SeriesIterator iterates over the data of a time series.
+type SeriesIterator interface {
+	// Seek advances the iterator forward to the given timestamp.
+	// If there's no value exactly at ts, it advances to the last value
+	// before tt.
+	Seek(t int64) bool
+	// Values returns the current timestamp/value pair.
+	Values() (t int64, v float64)
+	// Next advances the iterator by one.
+	Next() bool
+	// Err returns the current error.
+	Err() error
+}
diff --git a/writer.go b/writer.go
index 2adb50e6d..98e1fbbd7 100644
--- a/writer.go
+++ b/writer.go
@@ -7,7 +7,6 @@ import (
 	"io"
 	"os"
 	"sort"
-	"unsafe"
 )
 
 const (
@@ -60,10 +59,12 @@ func (w *seriesWriter) write(wr io.Writer, b []byte) error {
 }
 
 func (w *seriesWriter) writeMeta() error {
-	meta := &meta{magic: MagicSeries, flag: flagStd}
-	metab := ((*[metaSize]byte)(unsafe.Pointer(meta)))[:]
+	b := [64]byte{}
 
-	return w.write(w.w, metab)
+	binary.BigEndian.PutUint32(b[:4], MagicSeries)
+	b[4] = flagStd
+
+	return w.write(w.w, b[:])
 }
 
 func (w *seriesWriter) WriteSeries(ref uint32, lset Labels, chks []*chunkDesc) error {
@@ -78,13 +79,16 @@ func (w *seriesWriter) WriteSeries(ref uint32, lset Labels, chks []*chunkDesc) e
 	h := crc32.NewIEEE()
 	wr := io.MultiWriter(h, w.w)
 
-	l := uint32(0)
+	l := 0
 	for _, cd := range chks {
-		l += uint32(len(cd.chunk.Bytes()))
+		l += len(cd.chunk.Bytes())
 	}
 	// For normal reads we don't need the length of the chunk section but
 	// it allows us to verify checksums without reading the index file.
-	if err := w.write(wr, ((*[4]byte)(unsafe.Pointer(&l)))[:]); err != nil {
+	b := [4]byte{}
+	binary.BigEndian.PutUint32(b[:], uint32(l))
+
+	if err := w.write(wr, b[:]); err != nil {
 		return err
 	}
 
@@ -210,10 +214,11 @@ func (w *indexWriter) section(l uint32, flag byte, f func(w io.Writer) error) er
 	h := crc32.NewIEEE()
 	wr := io.MultiWriter(h, w.w)
 
-	if err := w.write(wr, ((*[4]byte)(unsafe.Pointer(&l)))[:]); err != nil {
-		return err
-	}
-	if err := w.write(wr, []byte{flagStd}); err != nil {
+	b := [5]byte{}
+	binary.BigEndian.PutUint32(b[:4], l)
+	b[4] = flagStd
+
+	if err := w.write(wr, b[:]); err != nil {
 		return err
 	}
 
@@ -224,10 +229,12 @@ func (w *indexWriter) section(l uint32, flag byte, f func(w io.Writer) error) er
 }
 
 func (w *indexWriter) writeMeta() error {
-	meta := &meta{magic: MagicSeries, flag: flagStd}
-	metab := ((*[metaSize]byte)(unsafe.Pointer(meta)))[:]
+	b := [64]byte{}
 
-	return w.write(w.w, metab)
+	binary.BigEndian.PutUint32(b[:4], MagicIndex)
+	b[4] = flagStd
+
+	return w.write(w.w, b[:])
 }
 
 func (w *indexWriter) AddSeries(ref uint32, lset Labels, offsets ...ChunkOffset) {
@@ -325,11 +332,11 @@ func (w *indexWriter) WriteLabelIndex(names []string, values []string) error {
 	return w.section(l, flagStd, func(wr io.Writer) error {
 		for _, v := range values {
 			o := w.symbols[v]
-			b := ((*[4]byte)(unsafe.Pointer(&o)))[:]
 
-			if err := w.write(wr, b); err != nil {
+			if err := binary.Write(wr, binary.BigEndian, o); err != nil {
 				return err
 			}
+			w.n += 4
 		}
 		return nil
 	})
@@ -344,10 +351,13 @@ func (w *indexWriter) WritePostings(name, value string, it Iterator) error {
 	})
 
 	b := make([]byte, 0, 4096)
+	buf := [4]byte{}
 
 	for it.Next() {
 		v := w.series[it.Value()].offset
-		b = append(b, ((*[4]byte)(unsafe.Pointer(&v)))[:]...)
+		binary.BigEndian.PutUint32(buf[:], v)
+
+		b = append(b, buf[:]...)
 	}
 
 	return w.section(uint32(len(b)), flagStd, func(wr io.Writer) error {
@@ -364,20 +374,21 @@ type hashEntry struct {
 	offset uint32
 }
 
-const hashEntrySize = uint32(unsafe.Sizeof(hashEntry{}))
-
 func (w *indexWriter) writeHashmap(h []hashEntry) error {
-	l := uint32(len(h)) * hashEntrySize
+	b := make([]byte, 0, 4096)
+	buf := make([]byte, 4)
 
-	return w.section(l, flagStd, func(wr io.Writer) error {
-		for _, e := range w.labelIndexes {
-			b := ((*[hashEntrySize]byte)(unsafe.Pointer(&e)))[:]
+	for _, e := range h {
+		binary.PutUvarint(buf, uint64(len(e.name)))
+		b = append(b, buf...)
+		b = append(b, e.name...)
 
-			if err := w.write(w.w, b); err != nil {
-				return nil
-			}
-		}
-		return nil
+		binary.BigEndian.PutUint32(buf, e.offset)
+		b = append(b, buf...)
+	}
+
+	return w.section(uint32(len(buf)), flagStd, func(wr io.Writer) error {
+		return w.write(wr, b)
 	})
 }
 
@@ -399,14 +410,11 @@ func (w *indexWriter) finalize() error {
 	// iteration over all existing series?
 	// TODO(fabxc): store references like these that are not resolved via direct
 	// mmap using explicit endianness?
-	if err := w.write(w.w, ((*[hashEntrySize]byte)(unsafe.Pointer(&lo)))[:]); err != nil {
-		return err
-	}
-	if err := w.write(w.w, ((*[hashEntrySize]byte)(unsafe.Pointer(&po)))[:]); err != nil {
-		return err
-	}
+	b := [8]byte{}
+	binary.BigEndian.PutUint32(b[:4], lo)
+	binary.BigEndian.PutUint32(b[4:], po)
 
-	return nil
+	return w.write(w.w, b[:])
 }
 
 func (w *indexWriter) Close() error {