core, cmd, vendor: fixes and database inspection tool (#15)

* core, eth: some fixes for freezer

* vendor, core/rawdb, cmd/geth: add db inspector

* core, cmd/utils: check ancient store path forceily

* cmd/geth, common, core/rawdb: a few fixes

* cmd/geth: support windows file rename and fix rename error

* core: support ancient plugin

* core, cmd: streaming file copy

* cmd, consensus, core, tests: keep genesis in leveldb

* core: write txlookup during ancient init

* core: bump database version

11 files changed, 353 insertions, 67 deletions

diff --git a/core/blockchain.go b/core/blockchain.go
index 4ac2c3a44..651c67c5d 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -93,7 +93,10 @@ const (
 	// - Version 6
 	//  The following incompatible database changes were added:
 	//    * Transaction lookup information stores the corresponding block number instead of block hash
-	BlockChainVersion uint64 = 6
+	// - Version 7
+	//  The following incompatible database changes were added:
+	//    * Use freezer as the ancient database to maintain all ancient data
+	BlockChainVersion uint64 = 7
 )
 
 // CacheConfig contains the configuration values for the trie caching/pruning
@@ -215,10 +218,35 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, chainConfig *par
 	if bc.genesisBlock == nil {
 		return nil, ErrNoGenesis
 	}
+	// Initialize the chain with ancient data if it isn't empty.
+	if bc.empty() {
+		if frozen, err := bc.db.Ancients(); err == nil && frozen > 0 {
+			for i := uint64(0); i < frozen; i++ {
+				// Inject hash<->number mapping.
+				hash := rawdb.ReadCanonicalHash(bc.db, i)
+				if hash == (common.Hash{}) {
+					return nil, errors.New("broken ancient database")
+				}
+				rawdb.WriteHeaderNumber(bc.db, hash, i)
+
+				// Inject txlookup indexes.
+				block := rawdb.ReadBlock(bc.db, hash, i)
+				if block == nil {
+					return nil, errors.New("broken ancient database")
+				}
+				rawdb.WriteTxLookupEntries(bc.db, block)
+			}
+			hash := rawdb.ReadCanonicalHash(bc.db, frozen-1)
+			rawdb.WriteHeadHeaderHash(bc.db, hash)
+			rawdb.WriteHeadFastBlockHash(bc.db, hash)
+
+			log.Info("Initialized chain with ancients", "number", frozen-1, "hash", hash)
+		}
+	}
 	if err := bc.loadLastState(); err != nil {
 		return nil, err
 	}
-	if frozen, err := bc.db.Ancients(); err == nil && frozen >= 1 {
+	if frozen, err := bc.db.Ancients(); err == nil && frozen > 0 {
 		var (
 			needRewind bool
 			low        uint64
@@ -278,6 +306,20 @@ func (bc *BlockChain) GetVMConfig() *vm.Config {
 	return &bc.vmConfig
 }
 
+// empty returns an indicator whether the blockchain is empty.
+// Note, it's a special case that we connect a non-empty ancient
+// database with an empty node, so that we can plugin the ancient
+// into node seamlessly.
+func (bc *BlockChain) empty() bool {
+	genesis := bc.genesisBlock.Hash()
+	for _, hash := range []common.Hash{rawdb.ReadHeadBlockHash(bc.db), rawdb.ReadHeadHeaderHash(bc.db), rawdb.ReadHeadFastBlockHash(bc.db)} {
+		if hash != genesis {
+			return false
+		}
+	}
+	return true
+}
+
 // loadLastState loads the last known chain state from the database. This method
 // assumes that the chain manager mutex is held.
 func (bc *BlockChain) loadLastState() error {
@@ -383,7 +425,9 @@ func (bc *BlockChain) SetHead(head uint64) error {
 		if num+1 <= frozen {
 			// Truncate all relative data(header, total difficulty, body, receipt
 			// and canonical hash) from ancient store.
-			bc.db.TruncateAncients(num + 1)
+			if err := bc.db.TruncateAncients(num + 1); err != nil {
+				log.Crit("Failed to truncate ancient data", "number", num, "err", err)
+			}
 
 			// Remove the hash <-> number mapping from the active store.
 			rawdb.DeleteHeaderNumber(db, hash)
@@ -948,6 +992,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 				}
 			}
 		}()
+		var deleted types.Blocks
 		for i, block := range blockChain {
 			// Short circuit insertion if shutting down or processing failed
 			if atomic.LoadInt32(&bc.procInterrupt) == 1 {
@@ -961,16 +1006,38 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 			if !bc.HasHeader(block.Hash(), block.NumberU64()) {
 				return i, fmt.Errorf("containing header #%d [%x…] unknown", block.Number(), block.Hash().Bytes()[:4])
 			}
-			// Compute all the non-consensus fields of the receipts
-			if err := receiptChain[i].DeriveFields(bc.chainConfig, block.Hash(), block.NumberU64(), block.Transactions()); err != nil {
-				return i, fmt.Errorf("failed to derive receipts data: %v", err)
+			var (
+				start  = time.Now()
+				logged = time.Now()
+				count  int
+			)
+			// Migrate all ancient blocks. This can happen if someone upgrades from Geth
+			// 1.8.x to 1.9.x mid-fast-sync. Perhaps we can get rid of this path in the
+			// long term.
+			for {
+				// We can ignore the error here since light client won't hit this code path.
+				frozen, _ := bc.db.Ancients()
+				if frozen >= block.NumberU64() {
+					break
+				}
+				h := rawdb.ReadCanonicalHash(bc.db, frozen)
+				b := rawdb.ReadBlock(bc.db, h, frozen)
+				size += rawdb.WriteAncientBlock(bc.db, b, rawdb.ReadReceipts(bc.db, h, frozen, bc.chainConfig), rawdb.ReadTd(bc.db, h, frozen))
+				count += 1
+
+				// Always keep genesis block in active database.
+				if b.NumberU64() != 0 {
+					deleted = append(deleted, b)
+				}
+				if time.Since(logged) > 8*time.Second {
+					log.Info("Migrating ancient blocks", "count", count, "elapsed", common.PrettyDuration(time.Since(start)))
+					logged = time.Now()
+				}
 			}
-			// Initialize freezer with genesis block first
-			if frozen, err := bc.db.Ancients(); err == nil && frozen == 0 && block.NumberU64() == 1 {
-				genesisBlock := rawdb.ReadBlock(bc.db, rawdb.ReadCanonicalHash(bc.db, 0), 0)
-				size += rawdb.WriteAncientBlock(bc.db, genesisBlock, nil, genesisBlock.Difficulty())
+			if count > 0 {
+				log.Info("Migrated ancient blocks", "count", count, "elapsed", common.PrettyDuration(time.Since(start)))
 			}
-			// Flush data into ancient store.
+			// Flush data into ancient database.
 			size += rawdb.WriteAncientBlock(bc.db, block, receiptChain[i], bc.GetTd(block.Hash(), block.NumberU64()))
 			rawdb.WriteTxLookupEntries(batch, block)
 
@@ -992,15 +1059,8 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 		}
 		previous = nil // disable rollback explicitly
 
-		// Remove the ancient data from the active store
-		cleanGenesis := len(blockChain) > 0 && blockChain[0].NumberU64() == 1
-		if cleanGenesis {
-			// Migrate genesis block to ancient store too.
-			rawdb.DeleteBlockWithoutNumber(batch, rawdb.ReadCanonicalHash(bc.db, 0), 0)
-			rawdb.DeleteCanonicalHash(batch, 0)
-		}
 		// Wipe out canonical block data.
-		for _, block := range blockChain {
+		for _, block := range append(deleted, blockChain...) {
 			rawdb.DeleteBlockWithoutNumber(batch, block.Hash(), block.NumberU64())
 			rawdb.DeleteCanonicalHash(batch, block.NumberU64())
 		}
@@ -1008,8 +1068,9 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 			return 0, err
 		}
 		batch.Reset()
+
 		// Wipe out side chain too.
-		for _, block := range blockChain {
+		for _, block := range append(deleted, blockChain...) {
 			for _, hash := range rawdb.ReadAllHashes(bc.db, block.NumberU64()) {
 				rawdb.DeleteBlock(batch, hash, block.NumberU64())
 			}
@@ -1035,10 +1096,6 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 				stats.ignored++
 				continue
 			}
-			// Compute all the non-consensus fields of the receipts
-			if err := receiptChain[i].DeriveFields(bc.chainConfig, block.Hash(), block.NumberU64(), block.Transactions()); err != nil {
-				return i, fmt.Errorf("failed to derive receipts data: %v", err)
-			}
 			// Write all the data out into the database
 			rawdb.WriteBody(batch, block.Hash(), block.NumberU64(), block.Body())
 			rawdb.WriteReceipts(batch, block.Hash(), block.NumberU64(), receiptChain[i])
diff --git a/core/blockchain_test.go b/core/blockchain_test.go
index 7b1a9a54f..09caf7e60 100644
--- a/core/blockchain_test.go
+++ b/core/blockchain_test.go
@@ -716,6 +716,20 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	height := uint64(1024)
 	blocks, receipts := GenerateChain(gspec.Config, genesis, ethash.NewFaker(), gendb, int(height), nil)
 
+	// makeDb creates a db instance for testing.
+	makeDb := func() (ethdb.Database, func()) {
+		dir, err := ioutil.TempDir("", "")
+		if err != nil {
+			t.Fatalf("failed to create temp freezer dir: %v", err)
+		}
+		defer os.Remove(dir)
+		db, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), dir, "")
+		if err != nil {
+			t.Fatalf("failed to create temp freezer db: %v", err)
+		}
+		gspec.MustCommit(db)
+		return db, func() { os.RemoveAll(dir) }
+	}
 	// Configure a subchain to roll back
 	remove := []common.Hash{}
 	for _, block := range blocks[height/2:] {
@@ -734,9 +748,8 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 		}
 	}
 	// Import the chain as an archive node and ensure all pointers are updated
-	archiveDb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(archiveDb)
-
+	archiveDb, delfn := makeDb()
+	defer delfn()
 	archive, _ := NewBlockChain(archiveDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{}, nil)
 	if n, err := archive.InsertChain(blocks); err != nil {
 		t.Fatalf("failed to process block %d: %v", n, err)
@@ -748,8 +761,8 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	assert(t, "archive", archive, height/2, height/2, height/2)
 
 	// Import the chain as a non-archive node and ensure all pointers are updated
-	fastDb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(fastDb)
+	fastDb, delfn := makeDb()
+	defer delfn()
 	fast, _ := NewBlockChain(fastDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{}, nil)
 	defer fast.Stop()
 
@@ -768,16 +781,8 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	assert(t, "fast", fast, height/2, height/2, 0)
 
 	// Import the chain as a ancient-first node and ensure all pointers are updated
-	frdir, err := ioutil.TempDir("", "")
-	if err != nil {
-		t.Fatalf("failed to create temp freezer dir: %v", err)
-	}
-	defer os.Remove(frdir)
-	ancientDb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), frdir, "")
-	if err != nil {
-		t.Fatalf("failed to create temp freezer db: %v", err)
-	}
-	gspec.MustCommit(ancientDb)
+	ancientDb, delfn := makeDb()
+	defer delfn()
 	ancient, _ := NewBlockChain(ancientDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{}, nil)
 	defer ancient.Stop()
 
@@ -795,9 +800,8 @@ func TestLightVsFastVsFullChainHeads(t *testing.T) {
 	}
 
 	// Import the chain as a light node and ensure all pointers are updated
-	lightDb := rawdb.NewMemoryDatabase()
-	gspec.MustCommit(lightDb)
-
+	lightDb, delfn := makeDb()
+	defer delfn()
 	light, _ := NewBlockChain(lightDb, nil, gspec.Config, ethash.NewFaker(), vm.Config{}, nil)
 	if n, err := light.InsertHeaderChain(headers, 1); err != nil {
 		t.Fatalf("failed to insert header %d: %v", n, err)
@@ -1892,10 +1896,18 @@ func testInsertKnownChainData(t *testing.T, typ string) {
 		b.SetCoinbase(common.Address{1})
 		b.OffsetTime(-9) // A higher difficulty
 	})
-
 	// Import the shared chain and the original canonical one
-	chaindb := rawdb.NewMemoryDatabase()
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("failed to create temp freezer dir: %v", err)
+	}
+	defer os.Remove(dir)
+	chaindb, err := rawdb.NewDatabaseWithFreezer(rawdb.NewMemoryDatabase(), dir, "")
+	if err != nil {
+		t.Fatalf("failed to create temp freezer db: %v", err)
+	}
 	new(Genesis).MustCommit(chaindb)
+	defer os.RemoveAll(dir)
 
 	chain, err := NewBlockChain(chaindb, nil, params.TestChainConfig, engine, vm.Config{}, nil)
 	if err != nil {
@@ -1992,18 +2004,16 @@ func testInsertKnownChainData(t *testing.T, typ string) {
 	// The head shouldn't change.
 	asserter(t, blocks3[len(blocks3)-1])
 
-	if typ != "headers" {
-		// Rollback the heavier chain and re-insert the longer chain again
-		for i := 0; i < len(blocks3); i++ {
-			rollback = append(rollback, blocks3[i].Hash())
-		}
-		chain.Rollback(rollback)
+	// Rollback the heavier chain and re-insert the longer chain again
+	for i := 0; i < len(blocks3); i++ {
+		rollback = append(rollback, blocks3[i].Hash())
+	}
+	chain.Rollback(rollback)
 
-		if err := inserter(append(blocks, blocks2...), append(receipts, receipts2...)); err != nil {
-			t.Fatalf("failed to insert chain data: %v", err)
-		}
-		asserter(t, blocks2[len(blocks2)-1])
+	if err := inserter(append(blocks, blocks2...), append(receipts, receipts2...)); err != nil {
+		t.Fatalf("failed to insert chain data: %v", err)
 	}
+	asserter(t, blocks2[len(blocks2)-1])
 }
 
 // getLongAndShortChains returns two chains,
diff --git a/core/genesis.go b/core/genesis.go
index 1f34a3a9e..830fb033b 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -170,6 +170,22 @@ func SetupGenesisBlockWithOverride(db ethdb.Database, genesis *Genesis, constant
 		return genesis.Config, block.Hash(), err
 	}
 
+	// We have the genesis block in database(perhaps in ancient database)
+	// but the corresponding state is missing.
+	header := rawdb.ReadHeader(db, stored, 0)
+	if _, err := state.New(header.Root, state.NewDatabaseWithCache(db, 0)); err != nil {
+		if genesis == nil {
+			genesis = DefaultGenesisBlock()
+		}
+		// Ensure the stored genesis matches with the given one.
+		hash := genesis.ToBlock(nil).Hash()
+		if hash != stored {
+			return genesis.Config, hash, &GenesisMismatchError{stored, hash}
+		}
+		block, err := genesis.Commit(db)
+		return genesis.Config, block.Hash(), err
+	}
+
 	// Check whether the genesis block is already written.
 	if genesis != nil {
 		hash := genesis.ToBlock(nil).Hash()
@@ -277,6 +293,7 @@ func (g *Genesis) Commit(db ethdb.Database) (*types.Block, error) {
 	rawdb.WriteReceipts(db, block.Hash(), block.NumberU64(), nil)
 	rawdb.WriteCanonicalHash(db, block.Hash(), block.NumberU64())
 	rawdb.WriteHeadBlockHash(db, block.Hash())
+	rawdb.WriteHeadFastBlockHash(db, block.Hash())
 	rawdb.WriteHeadHeaderHash(db, block.Hash())
 
 	config := g.Config
diff --git a/core/headerchain.go b/core/headerchain.go
index 659141fd1..cdd64bb50 100644
--- a/core/headerchain.go
+++ b/core/headerchain.go
@@ -274,9 +274,14 @@ func (hc *HeaderChain) InsertHeaderChain(chain []*types.Header, writeHeader WhCa
 			return i, errors.New("aborted")
 		}
 		// If the header's already known, skip it, otherwise store
-		if hc.HasHeader(header.Hash(), header.Number.Uint64()) {
-			stats.ignored++
-			continue
+		hash := header.Hash()
+		if hc.HasHeader(hash, header.Number.Uint64()) {
+			externTd := hc.GetTd(hash, header.Number.Uint64())
+			localTd := hc.GetTd(hc.currentHeaderHash, hc.CurrentHeader().Number.Uint64())
+			if externTd == nil || externTd.Cmp(localTd) <= 0 {
+				stats.ignored++
+				continue
+			}
 		}
 		if err := writeHeader(header); err != nil {
 			return i, err
diff --git a/core/rawdb/accessors_chain.go b/core/rawdb/accessors_chain.go
index 681e6e917..fab7ca56c 100644
--- a/core/rawdb/accessors_chain.go
+++ b/core/rawdb/accessors_chain.go
@@ -89,7 +89,16 @@ func ReadHeaderNumber(db ethdb.KeyValueReader, hash common.Hash) *uint64 {
 	return &number
 }
 
-// DeleteHeaderNumber removes hash to number mapping.
+// WriteHeaderNumber stores the hash->number mapping.
+func WriteHeaderNumber(db ethdb.KeyValueWriter, hash common.Hash, number uint64) {
+	key := headerNumberKey(hash)
+	enc := encodeBlockNumber(number)
+	if err := db.Put(key, enc); err != nil {
+		log.Crit("Failed to store hash to number mapping", "err", err)
+	}
+}
+
+// DeleteHeaderNumber removes hash->number mapping.
 func DeleteHeaderNumber(db ethdb.KeyValueWriter, hash common.Hash) {
 	if err := db.Delete(headerNumberKey(hash)); err != nil {
 		log.Crit("Failed to delete hash to number mapping", "err", err)
@@ -206,22 +215,19 @@ func ReadHeader(db ethdb.Reader, hash common.Hash, number uint64) *types.Header
 // WriteHeader stores a block header into the database and also stores the hash-
 // to-number mapping.
 func WriteHeader(db ethdb.KeyValueWriter, header *types.Header) {
-	// Write the hash -> number mapping
 	var (
-		hash    = header.Hash()
-		number  = header.Number.Uint64()
-		encoded = encodeBlockNumber(number)
+		hash   = header.Hash()
+		number = header.Number.Uint64()
 	)
-	key := headerNumberKey(hash)
-	if err := db.Put(key, encoded); err != nil {
-		log.Crit("Failed to store hash to number mapping", "err", err)
-	}
+	// Write the hash -> number mapping
+	WriteHeaderNumber(db, hash, number)
+
 	// Write the encoded header
 	data, err := rlp.EncodeToBytes(header)
 	if err != nil {
 		log.Crit("Failed to RLP encode header", "err", err)
 	}
-	key = headerKey(number, hash)
+	key := headerKey(number, hash)
 	if err := db.Put(key, data); err != nil {
 		log.Crit("Failed to store header", "err", err)
 	}
diff --git a/core/rawdb/accessors_metadata.go b/core/rawdb/accessors_metadata.go
index f8d09fbdd..e6235f010 100644
--- a/core/rawdb/accessors_metadata.go
+++ b/core/rawdb/accessors_metadata.go
@@ -80,6 +80,20 @@ func WriteChainConfig(db ethdb.KeyValueWriter, hash common.Hash, cfg *params.Cha
 	}
 }
 
+// ReadAncientPath retrieves ancient database path which is recorded during the
+// first node setup or forcibly changed by user.
+func ReadAncientPath(db ethdb.KeyValueReader) string {
+	data, _ := db.Get(ancientKey)
+	return string(data)
+}
+
+// WriteAncientPath writes ancient database path into the key-value database.
+func WriteAncientPath(db ethdb.KeyValueWriter, path string) {
+	if err := db.Put(ancientKey, []byte(path)); err != nil {
+		log.Crit("Failed to store ancient path", "err", err)
+	}
+}
+
 // ReadPreimage retrieves a single preimage of the provided hash.
 func ReadPreimage(db ethdb.KeyValueReader, hash common.Hash) []byte {
 	data, _ := db.Get(preimageKey(hash))
diff --git a/core/rawdb/database.go b/core/rawdb/database.go
index 5a3c7f94b..016c6c909 100644
--- a/core/rawdb/database.go
+++ b/core/rawdb/database.go
@@ -17,11 +17,17 @@
 package rawdb
 
 import (
+	"bytes"
 	"fmt"
+	"os"
+	"time"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/ethdb/leveldb"
 	"github.com/ethereum/go-ethereum/ethdb/memorydb"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/olekukonko/tablewriter"
 )
 
 // freezerdb is a database wrapper that enabled freezer data retrievals.
@@ -66,6 +72,11 @@ func (db *nofreezedb) Ancients() (uint64, error) {
 	return 0, errNotSupported
 }
 
+// AncientSize returns an error as we don't have a backing chain freezer.
+func (db *nofreezedb) AncientSize(kind string) (uint64, error) {
+	return 0, errNotSupported
+}
+
 // AppendAncient returns an error as we don't have a backing chain freezer.
 func (db *nofreezedb) AppendAncient(number uint64, hash, header, body, receipts, td []byte) error {
 	return errNotSupported
@@ -140,5 +151,128 @@ func NewLevelDBDatabaseWithFreezer(file string, cache int, handles int, freezer
 		kvdb.Close()
 		return nil, err
 	}
+	// Make sure we always use the same ancient store.
+	//
+	//                 | stored == nil    | stored != nil
+	// ----------------+------------------+----------------------
+	// freezer == nil  | non-freezer mode | ancient store missing
+	// freezer != nil  | initialize       | ensure consistency
+	stored := ReadAncientPath(kvdb)
+	if stored == "" && freezer != "" {
+		WriteAncientPath(kvdb, freezer)
+	} else if stored != freezer {
+		log.Warn("Ancient path mismatch", "stored", stored, "given", freezer)
+		log.Crit("Please use a consistent ancient path or migrate it via the command line tool `geth migrate-ancient`")
+	}
 	return frdb, nil
 }
+
+// InspectDatabase traverses the entire database and checks the size
+// of all different categories of data.
+func InspectDatabase(db ethdb.Database) error {
+	it := db.NewIterator()
+	defer it.Release()
+
+	var (
+		count  int64
+		start  = time.Now()
+		logged = time.Now()
+
+		// Key-value store statistics
+		total          common.StorageSize
+		headerSize     common.StorageSize
+		bodySize       common.StorageSize
+		receiptSize    common.StorageSize
+		tdSize         common.StorageSize
+		numHashPairing common.StorageSize
+		hashNumPairing common.StorageSize
+		trieSize       common.StorageSize
+		txlookupSize   common.StorageSize
+		preimageSize   common.StorageSize
+		bloomBitsSize  common.StorageSize
+
+		// Ancient store statistics
+		ancientHeaders  common.StorageSize
+		ancientBodies   common.StorageSize
+		ancientReceipts common.StorageSize
+		ancientHashes   common.StorageSize
+		ancientTds      common.StorageSize
+
+		// Les statistic
+		ChtTrieNodes   common.StorageSize
+		BloomTrieNodes common.StorageSize
+	)
+	// Inspect key-value database first.
+	for it.Next() {
+		var (
+			key  = it.Key()
+			size = common.StorageSize(len(key) + len(it.Value()))
+		)
+		total += size
+		switch {
+		case bytes.HasPrefix(key, headerPrefix) && bytes.HasSuffix(key, headerTDSuffix):
+			tdSize += size
+		case bytes.HasPrefix(key, headerPrefix) && bytes.HasSuffix(key, headerHashSuffix):
+			numHashPairing += size
+		case bytes.HasPrefix(key, headerPrefix) && len(key) == (len(headerPrefix)+8+common.HashLength):
+			headerSize += size
+		case bytes.HasPrefix(key, headerNumberPrefix) && len(key) == (len(headerNumberPrefix)+common.HashLength):
+			hashNumPairing += size
+		case bytes.HasPrefix(key, blockBodyPrefix) && len(key) == (len(blockBodyPrefix)+8+common.HashLength):
+			bodySize += size
+		case bytes.HasPrefix(key, blockReceiptsPrefix) && len(key) == (len(blockReceiptsPrefix)+8+common.HashLength):
+			receiptSize += size
+		case bytes.HasPrefix(key, txLookupPrefix) && len(key) == (len(txLookupPrefix)+common.HashLength):
+			txlookupSize += size
+		case bytes.HasPrefix(key, preimagePrefix) && len(key) == (len(preimagePrefix)+common.HashLength):
+			preimageSize += size
+		case bytes.HasPrefix(key, bloomBitsPrefix) && len(key) == (len(bloomBitsPrefix)+10+common.HashLength):
+			bloomBitsSize += size
+		case bytes.HasPrefix(key, []byte("cht-")) && len(key) == 4+common.HashLength:
+			ChtTrieNodes += size
+		case bytes.HasPrefix(key, []byte("blt-")) && len(key) == 4+common.HashLength:
+			BloomTrieNodes += size
+		case len(key) == common.HashLength:
+			trieSize += size
+		}
+		count += 1
+		if count%1000 == 0 && time.Since(logged) > 8*time.Second {
+			log.Info("Inspecting database", "count", count, "elapsed", common.PrettyDuration(time.Since(start)))
+			logged = time.Now()
+		}
+	}
+	// Inspect append-only file store then.
+	ancients := []*common.StorageSize{&ancientHeaders, &ancientBodies, &ancientReceipts, &ancientHashes, &ancientTds}
+	for i, category := range []string{freezerHeaderTable, freezerBodiesTable, freezerReceiptTable, freezerHashTable, freezerDifficultyTable} {
+		if size, err := db.AncientSize(category); err == nil {
+			*ancients[i] += common.StorageSize(size)
+			total += common.StorageSize(size)
+		}
+	}
+	// Display the database statistic.
+	stats := [][]string{
+		{"Key-Value store", "Headers", headerSize.String()},
+		{"Key-Value store", "Bodies", bodySize.String()},
+		{"Key-Value store", "Receipts", receiptSize.String()},
+		{"Key-Value store", "Difficulties", tdSize.String()},
+		{"Key-Value store", "Block number->hash", numHashPairing.String()},
+		{"Key-Value store", "Block hash->number", hashNumPairing.String()},
+		{"Key-Value store", "Transaction index", txlookupSize.String()},
+		{"Key-Value store", "Bloombit index", bloomBitsSize.String()},
+		{"Key-Value store", "Trie nodes", trieSize.String()},
+		{"Key-Value store", "Trie preimages", preimageSize.String()},
+		{"Ancient store", "Headers", ancientHeaders.String()},
+		{"Ancient store", "Bodies", ancientBodies.String()},
+		{"Ancient store", "Receipts", ancientReceipts.String()},
+		{"Ancient store", "Difficulties", ancientTds.String()},
+		{"Ancient store", "Block number->hash", ancientHashes.String()},
+		{"Light client", "CHT trie nodes", ChtTrieNodes.String()},
+		{"Light client", "Bloom trie nodes", BloomTrieNodes.String()},
+	}
+	table := tablewriter.NewWriter(os.Stdout)
+	table.SetHeader([]string{"Database", "Category", "Size"})
+	table.SetFooter([]string{"", "Total", total.String()})
+	table.AppendBulk(stats)
+	table.Render()
+	return nil
+}
diff --git a/core/rawdb/freezer.go b/core/rawdb/freezer.go
index 21a6055cd..f3a6bbb8f 100644
--- a/core/rawdb/freezer.go
+++ b/core/rawdb/freezer.go
@@ -20,6 +20,7 @@ import (
 	"errors"
 	"fmt"
 	"math"
+	"os"
 	"path/filepath"
 	"sync/atomic"
 	"time"
@@ -39,6 +40,10 @@ var (
 	// errOutOrderInsertion is returned if the user attempts to inject out-of-order
 	// binary blobs into the freezer.
 	errOutOrderInsertion = errors.New("the append operation is out-order")
+
+	// errSymlinkDatadir is returned if the ancient directory specified by user
+	// is a symbolic link.
+	errSymlinkDatadir = errors.New("symbolic link datadir is not supported")
 )
 
 const (
@@ -78,6 +83,13 @@ func newFreezer(datadir string, namespace string) (*freezer, error) {
 		readMeter  = metrics.NewRegisteredMeter(namespace+"ancient/read", nil)
 		writeMeter = metrics.NewRegisteredMeter(namespace+"ancient/write", nil)
 	)
+	// Ensure the datadir is not a symbolic link if it exists.
+	if info, err := os.Lstat(datadir); !os.IsNotExist(err) {
+		if info.Mode()&os.ModeSymlink != 0 {
+			log.Warn("Symbolic link ancient database is not supported", "path", datadir)
+			return nil, errSymlinkDatadir
+		}
+	}
 	// Leveldb uses LOCK as the filelock filename. To prevent the
 	// name collision, we use FLOCK as the lock name.
 	lock, _, err := fileutil.Flock(filepath.Join(datadir, "FLOCK"))
@@ -107,6 +119,7 @@ func newFreezer(datadir string, namespace string) (*freezer, error) {
 		lock.Release()
 		return nil, err
 	}
+	log.Info("Opened ancient database", "database", datadir)
 	return freezer, nil
 }
 
@@ -149,6 +162,14 @@ func (f *freezer) Ancients() (uint64, error) {
 	return atomic.LoadUint64(&f.frozen), nil
 }
 
+// AncientSize returns the ancient size of the specified category.
+func (f *freezer) AncientSize(kind string) (uint64, error) {
+	if table := f.tables[kind]; table != nil {
+		return table.size()
+	}
+	return 0, errUnknownTable
+}
+
 // AppendAncient injects all binary blobs belong to block at the end of the
 // append-only immutable table files.
 //
diff --git a/core/rawdb/freezer_table.go b/core/rawdb/freezer_table.go
index d46597f73..ebccf7816 100644
--- a/core/rawdb/freezer_table.go
+++ b/core/rawdb/freezer_table.go
@@ -515,6 +515,19 @@ func (t *freezerTable) has(number uint64) bool {
 	return atomic.LoadUint64(&t.items) > number
 }
 
+// size returns the total data size in the freezer table.
+func (t *freezerTable) size() (uint64, error) {
+	t.lock.RLock()
+	defer t.lock.RUnlock()
+
+	stat, err := t.index.Stat()
+	if err != nil {
+		return 0, err
+	}
+	total := uint64(t.maxFileSize)*uint64(t.headId-t.tailId) + uint64(t.headBytes) + uint64(stat.Size())
+	return total, nil
+}
+
 // Sync pushes any pending data from memory out to disk. This is an expensive
 // operation, so use it with care.
 func (t *freezerTable) Sync() error {
diff --git a/core/rawdb/schema.go b/core/rawdb/schema.go
index a44a2c99f..0d54a3c8b 100644
--- a/core/rawdb/schema.go
+++ b/core/rawdb/schema.go
@@ -41,6 +41,9 @@ var (
 	// fastTrieProgressKey tracks the number of trie entries imported during fast sync.
 	fastTrieProgressKey = []byte("TrieSync")
 
+	// ancientKey tracks the absolute path of ancient database.
+	ancientKey = []byte("AncientPath")
+
 	// Data item prefixes (use single byte to avoid mixing data types, avoid `i`, used for indexes).
 	headerPrefix       = []byte("h") // headerPrefix + num (uint64 big endian) + hash -> header
 	headerTDSuffix     = []byte("t") // headerPrefix + num (uint64 big endian) + hash + headerTDSuffix -> td
diff --git a/core/rawdb/table.go b/core/rawdb/table.go
index 124678959..6610b7f5a 100644
--- a/core/rawdb/table.go
+++ b/core/rawdb/table.go
@@ -68,6 +68,12 @@ func (t *table) Ancients() (uint64, error) {
 	return t.db.Ancients()
 }
 
+// AncientSize is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) AncientSize(kind string) (uint64, error) {
+	return t.db.AncientSize(kind)
+}
+
 // AppendAncient is a noop passthrough that just forwards the request to the underlying
 // database.
 func (t *table) AppendAncient(number uint64, hash, header, body, receipts, td []byte) error {