volume: check disk space before compaction

fix https://github.com/chrislusf/seaweedfs/issues/1440

weed/storage/store_vacuum.go

@@ -2,6 +2,7 @@ package storage
 
 import (
 	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/stats"
 
 	"github.com/chrislusf/seaweedfs/weed/glog"
 	"github.com/chrislusf/seaweedfs/weed/storage/needle"
@@ -16,6 +17,10 @@ func (s *Store) CheckCompactVolume(volumeId needle.VolumeId) (float64, error) {
 }
 func (s *Store) CompactVolume(vid needle.VolumeId, preallocate int64, compactionBytePerSecond int64) error {
 	if v := s.findVolume(vid); v != nil {
+		s := stats.NewDiskStatus(v.dir)
+		if int64(s.Free) < preallocate {
+			return fmt.Errorf("free space: %d bytes, not enough for %d bytes", s.Free, preallocate)
+		}
 		return v.Compact2(preallocate, compactionBytePerSecond)
 	}
 	return fmt.Errorf("volume id %d is not found during compact", vid)