diff --git a/pkg/sharky/recovery.go b/pkg/sharky/recovery.go
index 5a223e4c233..2b19ee93935 100644
--- a/pkg/sharky/recovery.go
+++ b/pkg/sharky/recovery.go
@@ -75,14 +75,7 @@ func (r *Recovery) Add(loc Location) error {
 func (r *Recovery) Read(ctx context.Context, loc Location, buf []byte) error {
 	r.mtx.Lock()
 	defer r.mtx.Unlock()
-
-	shFile := r.shardFiles[loc.Shard]
-	if stat, err := shFile.Stat(); err != nil {
-		return err
-	} else if stat.Size() < int64(loc.Slot)*int64(r.datasize) {
-		return errors.New("slot not found")
-	}
-	_, err := shFile.ReadAt(buf, int64(loc.Slot)*int64(r.datasize))
+	_, err := r.shardFiles[loc.Shard].ReadAt(buf, int64(loc.Slot)*int64(r.datasize))
 	return err
 }
 
diff --git a/pkg/sharky/shard.go b/pkg/sharky/shard.go
index e0b0909cc34..edb2faa8fee 100644
--- a/pkg/sharky/shard.go
+++ b/pkg/sharky/shard.go
@@ -7,6 +7,7 @@ package sharky
 import (
 	"context"
 	"encoding/binary"
+	"fmt"
 	"io"
 )
 
@@ -20,6 +21,10 @@ type Location struct {
 	Length uint16
 }
 
+func (l Location) String() string {
+	return fmt.Sprintf("shard: %d, slot: %d, length: %d", l.Shard, l.Slot, l.Length)
+}
+
 // MarshalBinary returns byte representation of location
 func (l *Location) MarshalBinary() ([]byte, error) {
 	b := make([]byte, LocationSize)
diff --git a/pkg/storer/compact.go b/pkg/storer/compact.go
index c44aab54e32..1cb6ebc14f8 100644
--- a/pkg/storer/compact.go
+++ b/pkg/storer/compact.go
@@ -93,13 +93,13 @@ func Compact(ctx context.Context, basePath string, opts *Options, validate bool)
 
 		for start < end {
 
-			if slots[end] == nil {
-				end-- // walk to the left until a used slot found
+			if slots[start] != nil {
+				start++ // walk to the right until a free slot is found
 				continue
 			}
 
-			if slots[start] != nil {
-				start++ // walk to the right until a free slot is found
+			if slots[end] == nil {
+				end-- // walk to the left until a used slot found
 				continue
 			}
 
@@ -154,7 +154,7 @@ func validationWork(logger log.Logger, store storage.Store, sharky *sharky.Recov
 	validChunk := func(item *chunkstore.RetrievalIndexItem, buf []byte) {
 		err := sharky.Read(context.Background(), item.Location, buf)
 		if err != nil {
-			logger.Warning("invalid chunk", "address", item.Address, "timestamp", time.Unix(int64(item.Timestamp), 0), "error", err)
+			logger.Warning("invalid chunk", "address", item.Address, "timestamp", time.Unix(int64(item.Timestamp), 0), "location", item.Location, "error", err)
 			return
 		}