diff --git a/core/src/main/kotlin/com/r3corda/core/contracts/TransactionGraphSearch.kt b/core/src/main/kotlin/com/r3corda/core/contracts/TransactionGraphSearch.kt
index 244cabf4a6..d43e69ebec 100644
--- a/core/src/main/kotlin/com/r3corda/core/contracts/TransactionGraphSearch.kt
+++ b/core/src/main/kotlin/com/r3corda/core/contracts/TransactionGraphSearch.kt
@@ -1,9 +1,7 @@
 package com.r3corda.core.contracts
 
-import com.r3corda.core.contracts.SignedTransaction
-import com.r3corda.core.contracts.WireTransaction
-import com.r3corda.core.contracts.CommandData
 import com.r3corda.core.crypto.SecureHash
+import com.r3corda.core.node.services.TransactionStorage
 import java.util.*
 import java.util.concurrent.Callable
 
@@ -17,7 +15,7 @@ import java.util.concurrent.Callable
  *
  * TODO: Write unit tests for this.
  */
-class TransactionGraphSearch(val transactions: Map<SecureHash, SignedTransaction>,
+class TransactionGraphSearch(val transactions: TransactionStorage,
                              val startPoints: List<WireTransaction>) : Callable<List<WireTransaction>> {
     class Query(
             val withCommandOfType: Class<out CommandData>? = null
@@ -35,7 +33,7 @@ class TransactionGraphSearch(val transactions: Map<SecureHash, SignedTransaction
 
         while (next.isNotEmpty()) {
             val hash = next.removeAt(next.lastIndex)
-            val tx = transactions[hash]?.tx ?: continue
+            val tx = transactions.getTransaction(hash)?.tx ?: continue
 
             if (q.matches(tx))
                 results += tx
diff --git a/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt b/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
index 1e6173c08c..a0e8c253bb 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/ServiceHub.kt
@@ -1,10 +1,8 @@
 package com.r3corda.core.node
 
 import com.r3corda.core.contracts.*
-import com.r3corda.core.crypto.SecureHash
 import com.r3corda.core.messaging.MessagingService
 import com.r3corda.core.node.services.*
-import com.r3corda.core.utilities.RecordingMap
 import java.time.Clock
 
 /**
@@ -31,7 +29,7 @@ interface ServiceHub {
      */
     fun verifyTransaction(ltx: LedgerTransaction) {
         val dependencies = ltx.inputs.map {
-            storageService.validatedTransactions[it.txhash] ?: throw TransactionResolutionException(it.txhash)
+            storageService.validatedTransactions.getTransaction(it.txhash) ?: throw TransactionResolutionException(it.txhash)
         }
         val ltxns = dependencies.map { it.verifyToLedgerTransaction(identityService, storageService.attachments) }
         TransactionGroup(setOf(ltx), ltxns.toSet()).verify()
@@ -42,18 +40,11 @@ interface ServiceHub {
      * sends them to the wallet for further processing.
      *
      * TODO: Need to come up with a way for preventing transactions being written other than by this method.
-     * TODO: RecordingMap is test infrastructure. Refactor it away or find a way to ensure it's only used in tests.
      *
      * @param txs The transactions to record
-     * @param skipRecordingMap This is used in unit testing and can be ignored most of the time.
      */
-    fun recordTransactions(txs: List<SignedTransaction>, skipRecordingMap: Boolean = false) {
-        val txns: Map<SecureHash, SignedTransaction> = txs.groupBy { it.id }.mapValues { it.value.first() }
-        val txStorage = storageService.validatedTransactions
-        if (txStorage is RecordingMap && skipRecordingMap)
-            txStorage.putAllUnrecorded(txns)
-        else
-            txStorage.putAll(txns)
+    fun recordTransactions(txs: List<SignedTransaction>) {
+        txs.forEach { storageService.validatedTransactions.addTransaction(it) }
         walletService.notifyAll(txs.map { it.tx })
     }
 
@@ -63,7 +54,7 @@ interface ServiceHub {
      * @throws TransactionResolutionException if the [StateRef] points to a non-existent transaction
      */
     fun loadState(stateRef: StateRef): ContractState {
-        val definingTx = storageService.validatedTransactions[stateRef.txhash] ?: throw TransactionResolutionException(stateRef.txhash)
+        val definingTx = storageService.validatedTransactions.getTransaction(stateRef.txhash) ?: throw TransactionResolutionException(stateRef.txhash)
         return definingTx.tx.outputs[stateRef.index]
     }
 }
\ No newline at end of file
diff --git a/core/src/main/kotlin/com/r3corda/core/node/services/Services.kt b/core/src/main/kotlin/com/r3corda/core/node/services/Services.kt
index 0535668b86..34a379b565 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/services/Services.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/services/Services.kt
@@ -3,7 +3,7 @@ package com.r3corda.core.node.services
 import com.r3corda.core.contracts.*
 import com.r3corda.core.crypto.Party
 import com.r3corda.core.crypto.SecureHash
-import com.r3corda.core.node.services.AttachmentStorage
+import com.r3corda.core.node.services.TransactionStorage
 import java.security.KeyPair
 import java.security.PrivateKey
 import java.security.PublicKey
@@ -123,7 +123,7 @@ interface StorageService {
      * The signatures aren't technically needed after that point, but we keep them around so that we can relay
      * the transaction data to other nodes that need it.
      */
-    val validatedTransactions: MutableMap<SecureHash, SignedTransaction>
+    val validatedTransactions: TransactionStorage
 
     /** Provides access to storage of arbitrary JAR files (which may contain only data, no code). */
     val attachments: AttachmentStorage
diff --git a/core/src/main/kotlin/com/r3corda/core/node/services/TransactionStorage.kt b/core/src/main/kotlin/com/r3corda/core/node/services/TransactionStorage.kt
new file mode 100644
index 0000000000..80b61f33fc
--- /dev/null
+++ b/core/src/main/kotlin/com/r3corda/core/node/services/TransactionStorage.kt
@@ -0,0 +1,22 @@
+package com.r3corda.core.node.services
+
+import com.r3corda.core.contracts.SignedTransaction
+import com.r3corda.core.crypto.SecureHash
+
+/**
+ * Thread-safe storage of transactions.
+ */
+interface TransactionStorage {
+
+    /**
+     * Add a new transaction to the store. If the store already has a transaction with the same id it will be
+     * overwritten.
+     */
+    fun addTransaction(transaction: SignedTransaction)
+
+    /**
+     * Return the transaction with the given [id], or null if no such transaction exists.
+     */
+    fun getTransaction(id: SecureHash): SignedTransaction?
+
+}
diff --git a/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt b/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
index 54647fca4a..db90aa5eef 100644
--- a/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
+++ b/core/src/main/kotlin/com/r3corda/core/node/services/testing/MockServices.kt
@@ -6,13 +6,8 @@ import com.r3corda.core.crypto.Party
 import com.r3corda.core.crypto.SecureHash
 import com.r3corda.core.crypto.generateKeyPair
 import com.r3corda.core.crypto.sha256
-import com.r3corda.core.node.services.AttachmentStorage
-import com.r3corda.core.node.services.IdentityService
-import com.r3corda.core.node.services.KeyManagementService
-import com.r3corda.core.node.services.StorageService
+import com.r3corda.core.node.services.*
 import com.r3corda.core.serialization.SingletonSerializeAsToken
-import com.r3corda.core.utilities.RecordingMap
-import org.slf4j.LoggerFactory
 import java.io.ByteArrayInputStream
 import java.io.ByteArrayOutputStream
 import java.io.File
@@ -82,33 +77,17 @@ class MockAttachmentStorage : AttachmentStorage {
     }
 }
 
+class MockTransactionStorage : TransactionStorage {
+    private val txns = HashMap<SecureHash, SignedTransaction>()
+    override fun addTransaction(transaction: SignedTransaction) {
+        txns[transaction.id] = transaction
+    }
+    override fun getTransaction(id: SecureHash): SignedTransaction? = txns[id]
+}
 
 @ThreadSafe
 class MockStorageService(override val attachments: AttachmentStorage = MockAttachmentStorage(),
+                         override val validatedTransactions: TransactionStorage = MockTransactionStorage(),
                          override val myLegalIdentityKey: KeyPair = generateKeyPair(),
-                         override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public),
-// This parameter is for unit tests that want to observe operation details.
-                         val recordingAs: (String) -> String = { tableName -> "" })
-: SingletonSerializeAsToken(), StorageService {
-    protected val tables = HashMap<String, MutableMap<*, *>>()
-
-    private fun <K, V> getMapOriginal(tableName: String): MutableMap<K, V> {
-        synchronized(tables) {
-            @Suppress("UNCHECKED_CAST")
-            return tables.getOrPut(tableName) {
-                recorderWrap(Collections.synchronizedMap(HashMap<K, V>()), tableName)
-            } as MutableMap<K, V>
-        }
-    }
-
-    private fun <K, V> recorderWrap(map: MutableMap<K, V>, tableName: String): MutableMap<K, V> {
-        if (recordingAs(tableName) != "")
-            return RecordingMap(map, LoggerFactory.getLogger("recordingmap.${recordingAs(tableName)}"))
-        else
-            return map
-    }
-
-    override val validatedTransactions: MutableMap<SecureHash, SignedTransaction>
-    get() = getMapOriginal("validated-transactions")
-
-}
+                         override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public))
+: SingletonSerializeAsToken(), StorageService
diff --git a/core/src/main/kotlin/com/r3corda/protocols/FetchTransactionsProtocol.kt b/core/src/main/kotlin/com/r3corda/protocols/FetchTransactionsProtocol.kt
index 864aeb7562..032fa9b583 100644
--- a/core/src/main/kotlin/com/r3corda/protocols/FetchTransactionsProtocol.kt
+++ b/core/src/main/kotlin/com/r3corda/protocols/FetchTransactionsProtocol.kt
@@ -18,6 +18,6 @@ class FetchTransactionsProtocol(requests: Set<SecureHash>, otherSide: SingleMess
         const val TOPIC = "platform.fetch.tx"
     }
 
-    override fun load(txid: SecureHash): SignedTransaction? = serviceHub.storageService.validatedTransactions[txid]
+    override fun load(txid: SecureHash): SignedTransaction? = serviceHub.storageService.validatedTransactions.getTransaction(txid)
     override val queryTopic: String = TOPIC
 }
\ No newline at end of file
diff --git a/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt b/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
index 364a6a8966..bc00eb2b94 100644
--- a/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
+++ b/node/src/main/kotlin/com/r3corda/node/internal/AbstractNode.kt
@@ -28,10 +28,7 @@ import com.r3corda.node.services.network.InMemoryNetworkMapCache
 import com.r3corda.node.services.network.InMemoryNetworkMapService
 import com.r3corda.node.services.network.NetworkMapService
 import com.r3corda.node.services.network.NodeRegistration
-import com.r3corda.node.services.persistence.DataVendingService
-import com.r3corda.node.services.persistence.NodeAttachmentService
-import com.r3corda.node.services.persistence.PerFileCheckpointStorage
-import com.r3corda.node.services.persistence.StorageServiceImpl
+import com.r3corda.node.services.persistence.*
 import com.r3corda.node.services.statemachine.StateMachineManager
 import com.r3corda.node.services.transactions.InMemoryUniquenessProvider
 import com.r3corda.node.services.transactions.NotaryService
@@ -257,13 +254,17 @@ abstract class AbstractNode(val dir: Path, val configuration: NodeConfiguration,
     protected open fun initialiseStorageService(dir: Path): Pair<StorageService, CheckpointStorage> {
         val attachments = makeAttachmentStorage(dir)
         val checkpointStorage = PerFileCheckpointStorage(dir.resolve("checkpoints"))
+        val transactionStorage = PerFileTransactionStorage(dir.resolve("transactions"))
         _servicesThatAcceptUploads += attachments
         val (identity, keypair) = obtainKeyPair(dir)
-        return Pair(constructStorageService(attachments, keypair, identity), checkpointStorage)
+        return Pair(constructStorageService(attachments, transactionStorage, keypair, identity),checkpointStorage)
     }
 
-    protected open fun constructStorageService(attachments: NodeAttachmentService, keypair: KeyPair, identity: Party) =
-            StorageServiceImpl(attachments, keypair, identity)
+    protected open fun constructStorageService(attachments: NodeAttachmentService,
+                                               transactionStorage: TransactionStorage,
+                                               keypair: KeyPair,
+                                               identity: Party) =
+            StorageServiceImpl(attachments, transactionStorage, keypair, identity)
 
     private fun obtainKeyPair(dir: Path): Pair<Party, KeyPair> {
         // Load the private identity key, creating it if necessary. The identity key is a long term well known key that
@@ -307,4 +308,4 @@ abstract class AbstractNode(val dir: Path, val configuration: NodeConfiguration,
         }
         return NodeAttachmentService(attachmentsDir, services.monitoringService.metrics)
     }
-}
\ No newline at end of file
+}
diff --git a/node/src/main/kotlin/com/r3corda/node/internal/testing/TradeSimulation.kt b/node/src/main/kotlin/com/r3corda/node/internal/testing/TradeSimulation.kt
index c8b209db25..6c5a8c6403 100644
--- a/node/src/main/kotlin/com/r3corda/node/internal/testing/TradeSimulation.kt
+++ b/node/src/main/kotlin/com/r3corda/node/internal/testing/TradeSimulation.kt
@@ -36,7 +36,7 @@ class TradeSimulation(runAsync: Boolean, latencyInjector: InMemoryMessagingNetwo
             tx.signWith(seller.storage.myLegalIdentityKey)
             tx.toSignedTransaction(true)
         }
-        seller.services.storageService.validatedTransactions[issuance.id] = issuance
+        seller.services.storageService.validatedTransactions.addTransaction(issuance)
 
         val sessionID = random63BitValue()
         val buyerProtocol = TwoPartyTradeProtocol.Buyer(seller.net.myAddress, notary.info.identity,
diff --git a/node/src/main/kotlin/com/r3corda/node/services/persistence/DataVendingService.kt b/node/src/main/kotlin/com/r3corda/node/services/persistence/DataVendingService.kt
index 47265b5994..43a09867ab 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/persistence/DataVendingService.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/persistence/DataVendingService.kt
@@ -3,8 +3,8 @@ package com.r3corda.node.services.persistence
 import com.r3corda.core.contracts.SignedTransaction
 import com.r3corda.core.messaging.MessagingService
 import com.r3corda.core.node.services.StorageService
-import com.r3corda.node.services.api.AbstractNodeService
 import com.r3corda.core.utilities.loggerFor
+import com.r3corda.node.services.api.AbstractNodeService
 import com.r3corda.protocols.FetchAttachmentsProtocol
 import com.r3corda.protocols.FetchDataProtocol
 import com.r3corda.protocols.FetchTransactionsProtocol
@@ -43,7 +43,7 @@ class DataVendingService(net: MessagingService, private val storage: StorageServ
     private fun handleTXRequest(req: FetchDataProtocol.Request): List<SignedTransaction?> {
         require(req.hashes.isNotEmpty())
         return req.hashes.map {
-            val tx = storage.validatedTransactions[it]
+            val tx = storage.validatedTransactions.getTransaction(it)
             if (tx == null)
                 logger.info("Got request for unknown tx $it")
             tx
diff --git a/node/src/main/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorage.kt b/node/src/main/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorage.kt
new file mode 100644
index 0000000000..6e063c5181
--- /dev/null
+++ b/node/src/main/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorage.kt
@@ -0,0 +1,48 @@
+package com.r3corda.node.services.persistence
+
+import com.r3corda.core.contracts.SignedTransaction
+import com.r3corda.core.crypto.SecureHash
+import com.r3corda.core.node.services.TransactionStorage
+import com.r3corda.core.serialization.deserialize
+import com.r3corda.core.serialization.serialize
+import com.r3corda.core.utilities.loggerFor
+import com.r3corda.core.utilities.trace
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.concurrent.ConcurrentHashMap
+import javax.annotation.concurrent.ThreadSafe
+
+/**
+ * File-based transaction storage, storing transactions per file.
+ */
+@ThreadSafe
+class PerFileTransactionStorage(val storeDir: Path) : TransactionStorage {
+
+    companion object {
+        private val logger = loggerFor<PerFileCheckpointStorage>()
+        private val fileExtension = ".transaction"
+    }
+
+    private val _transactions = ConcurrentHashMap<SecureHash, SignedTransaction>()
+
+    init {
+        logger.trace { "Initialising per file transaction storage on $storeDir" }
+        Files.createDirectories(storeDir)
+        Files.list(storeDir)
+                .filter { it.toString().toLowerCase().endsWith(fileExtension) }
+                .map { Files.readAllBytes(it).deserialize<SignedTransaction>() }
+                .forEach { _transactions[it.id] = it }
+    }
+
+    override fun addTransaction(transaction: SignedTransaction) {
+        val transactionFile = storeDir.resolve("${transaction.id.toString().toLowerCase()}$fileExtension")
+        transaction.serialize().writeToFile(transactionFile)
+        _transactions[transaction.id] = transaction
+        logger.trace { "Stored $transaction to $transactionFile" }
+    }
+
+    override fun getTransaction(id: SecureHash): SignedTransaction? = _transactions[id]
+
+    val transactions: Iterable<SignedTransaction> get() = _transactions.values.toList()
+
+}
\ No newline at end of file
diff --git a/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt b/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
index 86a485773e..a6b9c0f906 100644
--- a/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
+++ b/node/src/main/kotlin/com/r3corda/node/services/persistence/StorageServiceImpl.kt
@@ -1,41 +1,14 @@
 package com.r3corda.node.services.persistence
 
-import com.r3corda.core.contracts.SignedTransaction
 import com.r3corda.core.crypto.Party
-import com.r3corda.core.crypto.SecureHash
 import com.r3corda.core.node.services.AttachmentStorage
 import com.r3corda.core.node.services.StorageService
+import com.r3corda.core.node.services.TransactionStorage
 import com.r3corda.core.serialization.SingletonSerializeAsToken
-import com.r3corda.core.utilities.RecordingMap
-import org.slf4j.LoggerFactory
 import java.security.KeyPair
-import java.util.*
 
 open class StorageServiceImpl(override val attachments: AttachmentStorage,
+                              override val validatedTransactions: TransactionStorage,
                               override val myLegalIdentityKey: KeyPair,
-                              override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public),
-                              // This parameter is for unit tests that want to observe operation details.
-                              val recordingAs: (String) -> String = { tableName -> "" })
-: SingletonSerializeAsToken(), StorageService {
-    protected val tables = HashMap<String, MutableMap<*, *>>()
-
-    private fun <K, V> getMapOriginal(tableName: String): MutableMap<K, V> {
-        synchronized(tables) {
-            @Suppress("UNCHECKED_CAST")
-            return tables.getOrPut(tableName) {
-                recorderWrap(Collections.synchronizedMap(HashMap<K, V>()), tableName)
-            } as MutableMap<K, V>
-        }
-    }
-
-    private fun <K, V> recorderWrap(map: MutableMap<K, V>, tableName: String): MutableMap<K, V> {
-        if (recordingAs(tableName) != "")
-            return RecordingMap(map, LoggerFactory.getLogger("recordingmap.${recordingAs(tableName)}"))
-        else
-            return map
-    }
-
-    override val validatedTransactions: MutableMap<SecureHash, SignedTransaction>
-        get() = getMapOriginal("validated-transactions")
-
-}
\ No newline at end of file
+                              override val myLegalIdentity: Party = Party("Unit test party", myLegalIdentityKey.public))
+: SingletonSerializeAsToken(), StorageService
diff --git a/node/src/test/kotlin/com/r3corda/node/messaging/TwoPartyTradeProtocolTests.kt b/node/src/test/kotlin/com/r3corda/node/messaging/TwoPartyTradeProtocolTests.kt
index 3b9e41d300..3a45fbe148 100644
--- a/node/src/test/kotlin/com/r3corda/node/messaging/TwoPartyTradeProtocolTests.kt
+++ b/node/src/test/kotlin/com/r3corda/node/messaging/TwoPartyTradeProtocolTests.kt
@@ -1,8 +1,8 @@
 package com.r3corda.node.messaging
 
 import com.google.common.util.concurrent.ListenableFuture
-import com.r3corda.contracts.cash.Cash
 import com.r3corda.contracts.CommercialPaper
+import com.r3corda.contracts.cash.Cash
 import com.r3corda.contracts.testing.CASH
 import com.r3corda.contracts.testing.`issued by`
 import com.r3corda.contracts.testing.`owned by`
@@ -14,16 +14,17 @@ import com.r3corda.core.messaging.SingleMessageRecipient
 import com.r3corda.core.node.NodeInfo
 import com.r3corda.core.node.ServiceHub
 import com.r3corda.core.node.services.ServiceType
+import com.r3corda.core.node.services.TransactionStorage
 import com.r3corda.core.node.services.Wallet
 import com.r3corda.core.random63BitValue
 import com.r3corda.core.seconds
 import com.r3corda.core.testing.*
 import com.r3corda.core.utilities.BriefLogFormatter
-import com.r3corda.core.utilities.RecordingMap
 import com.r3corda.node.internal.testing.MockNetwork
 import com.r3corda.node.services.config.NodeConfiguration
 import com.r3corda.node.services.network.InMemoryMessagingNetwork
 import com.r3corda.node.services.persistence.NodeAttachmentService
+import com.r3corda.node.services.persistence.PerFileTransactionStorage
 import com.r3corda.node.services.persistence.StorageServiceImpl
 import com.r3corda.node.services.statemachine.StateMachineManager
 import com.r3corda.node.services.wallet.NodeWalletService
@@ -38,13 +39,12 @@ import java.io.ByteArrayOutputStream
 import java.nio.file.Path
 import java.security.KeyPair
 import java.security.PublicKey
-import java.util.Currency
+import java.util.*
 import java.util.concurrent.ExecutionException
 import java.util.jar.JarOutputStream
 import java.util.zip.ZipEntry
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
-import kotlin.test.assertNotNull
 import kotlin.test.assertTrue
 
 /**
@@ -186,15 +186,15 @@ class TwoPartyTradeProtocolTests {
             // OK, now Bob has sent the partial transaction back to Alice and is waiting for Alice's signature.
             assertThat(bobNode.checkpointStorage.checkpoints).hasSize(1)
 
-            // TODO: remove once validated transactions are persisted to disk
-            val recordedTransactions = bobNode.storage.validatedTransactions
+            val bobTransactionsBeforeCrash = (bobNode.storage.validatedTransactions as PerFileTransactionStorage).transactions
+            assertThat(bobTransactionsBeforeCrash).isNotEmpty()
 
             // .. and let's imagine that Bob's computer has a power cut. He now has nothing now beyond what was on disk.
             bobNode.stop()
 
             // Alice doesn't know that and carries on: she wants to know about the cash transactions he's trying to use.
             // She will wait around until Bob comes back.
-            assertNotNull(pumpAlice())
+            assertThat(pumpAlice()).isNotNull()
 
             // ... bring the node back up ... the act of constructing the SMM will re-register the message handlers
             // that Bob was waiting on before the reboot occurred.
@@ -205,9 +205,6 @@ class TwoPartyTradeProtocolTests {
                 }
             }, true, BOB.name, BOB_KEY)
 
-            // TODO: remove once validated transactions are persisted to disk
-            bobNode.storage.validatedTransactions.putAll(recordedTransactions)
-
             // Find the future representing the result of this state machine again.
             val bobFuture = bobNode.smm.findStateMachines(TwoPartyTradeProtocol.Buyer::class.java).single().second
 
@@ -215,12 +212,15 @@ class TwoPartyTradeProtocolTests {
             net.runNetwork()
 
             // Bob is now finished and has the same transaction as Alice.
-            assertEquals(bobFuture.get(), aliceFuture.get())
+            assertThat(bobFuture.get()).isEqualTo(aliceFuture.get())
 
             assertThat(bobNode.smm.findStateMachines(TwoPartyTradeProtocol.Buyer::class.java)).isEmpty()
 
             assertThat(bobNode.checkpointStorage.checkpoints).isEmpty()
             assertThat(aliceNode.checkpointStorage.checkpoints).isEmpty()
+
+            val restoredBobTransactions = bobTransactionsBeforeCrash.filter { bobNode.storage.validatedTransactions.getTransaction(it.id) != null }
+            assertThat(restoredBobTransactions).containsAll(bobTransactionsBeforeCrash)
         }
     }
 
@@ -233,9 +233,11 @@ class TwoPartyTradeProtocolTests {
                                 advertisedServices: Set<ServiceType>, id: Int, keyPair: KeyPair?): MockNetwork.MockNode {
                 return object : MockNetwork.MockNode(dir, config, network, networkMapAddr, advertisedServices, id, keyPair) {
                     // That constructs the storage service object in a customised way ...
-                    override fun constructStorageService(attachments: NodeAttachmentService, keypair: KeyPair, identity: Party): StorageServiceImpl {
-                        // To use RecordingMaps instead of ordinary HashMaps.
-                        return StorageServiceImpl(attachments, keypair, identity, { tableName -> name })
+                    override fun constructStorageService(attachments: NodeAttachmentService,
+                                                         transactionStorage: TransactionStorage,
+                                                         keypair: KeyPair,
+                                                         identity: Party): StorageServiceImpl {
+                        return StorageServiceImpl(attachments, RecordingTransactionStorage(transactionStorage), keypair, identity)
                     }
                 }
             }
@@ -243,7 +245,7 @@ class TwoPartyTradeProtocolTests {
     }
 
     @Test
-    fun checkDependenciesOfSaleAssetAreResolved() {
+    fun `check dependencies of sale asset are resolved`() {
         transactionGroupFor<ContractState> {
             val notaryNode = net.createNotaryNode(DUMMY_NOTARY.name, DUMMY_NOTARY_KEY)
             val aliceNode = makeNodeWithTracking(notaryNode.info, ALICE.name, ALICE_KEY)
@@ -289,22 +291,21 @@ class TwoPartyTradeProtocolTests {
             net.runNetwork()
 
             run {
-                val records = (bobNode.storage.validatedTransactions as RecordingMap).records
+                val records = (bobNode.storage.validatedTransactions as RecordingTransactionStorage).records
                 // Check Bobs's database accesses as Bob's cash transactions are downloaded by Alice.
-                val expected = listOf(
+                assertThat(records).containsExactly(
                         // Buyer Bob is told about Alice's commercial paper, but doesn't know it ..
-                        RecordingMap.Get(alicesFakePaper[0].id),
+                        TxRecord.Get(alicesFakePaper[0].id),
                         // He asks and gets the tx, validates it, sees it's a self issue with no dependencies, stores.
-                        RecordingMap.Put(alicesFakePaper[0].id, alicesSignedTxns.values.first()),
+                        TxRecord.Add(alicesSignedTxns.values.first()),
                         // Alice gets Bob's proposed transaction and doesn't know his two cash states. She asks, Bob answers.
-                        RecordingMap.Get(bobsFakeCash[1].id),
-                        RecordingMap.Get(bobsFakeCash[2].id),
+                        TxRecord.Get(bobsFakeCash[1].id),
+                        TxRecord.Get(bobsFakeCash[2].id),
                         // Alice notices that Bob's cash txns depend on a third tx she also doesn't know. She asks, Bob answers.
-                        RecordingMap.Get(bobsFakeCash[0].id),
+                        TxRecord.Get(bobsFakeCash[0].id),
                         // Bob wants to verify that the tx has been signed by the correct Notary, which requires looking up an input state
-                        RecordingMap.Get(bobsFakeCash[1].id)
+                        TxRecord.Get(bobsFakeCash[1].id)
                 )
-                assertEquals(expected, records)
 
                 // Bob has downloaded the attachment.
                 bobNode.storage.attachments.openAttachment(attachmentID)!!.openAsJAR().use {
@@ -316,33 +317,32 @@ class TwoPartyTradeProtocolTests {
 
             // And from Alice's perspective ...
             run {
-                val records = (aliceNode.storage.validatedTransactions as RecordingMap).records
-                val expected = listOf(
+                val records = (aliceNode.storage.validatedTransactions as RecordingTransactionStorage).records
+                assertThat(records).containsExactly(
                         // Seller Alice sends her seller info to Bob, who wants to check the asset for sale.
                         // He requests, Alice looks up in her DB to send the tx to Bob
-                        RecordingMap.Get(alicesFakePaper[0].id),
+                        TxRecord.Get(alicesFakePaper[0].id),
                         // Seller Alice gets a proposed tx which depends on Bob's two cash txns and her own tx.
-                        RecordingMap.Get(bobsFakeCash[1].id),
-                        RecordingMap.Get(bobsFakeCash[2].id),
-                        RecordingMap.Get(alicesFakePaper[0].id),
+                        TxRecord.Get(bobsFakeCash[1].id),
+                        TxRecord.Get(bobsFakeCash[2].id),
+                        TxRecord.Get(alicesFakePaper[0].id),
                         // Alice notices that Bob's cash txns depend on a third tx she also doesn't know.
-                        RecordingMap.Get(bobsFakeCash[0].id),
+                        TxRecord.Get(bobsFakeCash[0].id),
                         // Bob answers with the transactions that are now all verifiable, as Alice bottomed out.
                         // Bob's transactions are valid, so she commits to the database
-                        RecordingMap.Put(bobsFakeCash[1].id, bobsSignedTxns[bobsFakeCash[1].id]),
-                        RecordingMap.Put(bobsFakeCash[2].id, bobsSignedTxns[bobsFakeCash[2].id]),
-                        RecordingMap.Put(bobsFakeCash[0].id, bobsSignedTxns[bobsFakeCash[0].id]),
+                        TxRecord.Add(bobsSignedTxns[bobsFakeCash[1].id]!!),
+                        TxRecord.Add(bobsSignedTxns[bobsFakeCash[2].id]!!),
+                        TxRecord.Add(bobsSignedTxns[bobsFakeCash[0].id]!!),
                         // Now she verifies the transaction is contract-valid (not signature valid) which means
                         // looking up the states again.
-                        RecordingMap.Get(bobsFakeCash[1].id),
-                        RecordingMap.Get(bobsFakeCash[2].id),
-                        RecordingMap.Get(alicesFakePaper[0].id),
+                        TxRecord.Get(bobsFakeCash[1].id),
+                        TxRecord.Get(bobsFakeCash[2].id),
+                        TxRecord.Get(alicesFakePaper[0].id),
                         // Alice needs to look up the input states to find out which Notary they point to
-                        RecordingMap.Get(bobsFakeCash[1].id),
-                        RecordingMap.Get(bobsFakeCash[2].id),
-                        RecordingMap.Get(alicesFakePaper[0].id)
+                        TxRecord.Get(bobsFakeCash[1].id),
+                        TxRecord.Get(bobsFakeCash[2].id),
+                        TxRecord.Get(alicesFakePaper[0].id)
                 )
-                assertEquals(expected, records)
             }
         }
     }
@@ -415,7 +415,11 @@ class TwoPartyTradeProtocolTests {
                                                                           services: ServiceHub,
                                                                           vararg extraKeys: KeyPair): Map<SecureHash, SignedTransaction> {
         val signed: List<SignedTransaction> = signAll(wtxToSign, *extraKeys)
-        services.recordTransactions(signed, skipRecordingMap = true)
+        services.recordTransactions(signed)
+        val validatedTransactions = services.storageService.validatedTransactions
+        if (validatedTransactions is RecordingTransactionStorage) {
+            validatedTransactions.records.clear()
+        }
         return signed.associateBy { it.id }
     }
 
@@ -465,4 +469,27 @@ class TwoPartyTradeProtocolTests {
         val wallet = WalletImpl(listOf<StateAndRef<Cash.State>>(lookup("alice's paper")))
         return Pair(wallet, listOf(ap))
     }
+
+
+    class RecordingTransactionStorage(val delegate: TransactionStorage) : TransactionStorage {
+
+        val records = Collections.synchronizedList(ArrayList<TxRecord>())
+
+        override fun addTransaction(transaction: SignedTransaction) {
+            records.add(TxRecord.Add(transaction))
+            delegate.addTransaction(transaction)
+        }
+
+        override fun getTransaction(id: SecureHash): SignedTransaction? {
+            records.add(TxRecord.Get(id))
+            return delegate.getTransaction(id)
+        }
+    }
+
+    interface TxRecord {
+        data class Add(val transaction: SignedTransaction) : TxRecord
+        data class Get(val id: SecureHash): TxRecord
+    }
+
+
 }
diff --git a/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt b/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
index b4331bf88a..9fb51f1065 100644
--- a/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
+++ b/node/src/test/kotlin/com/r3corda/node/services/MockServices.kt
@@ -6,8 +6,6 @@ import com.r3corda.core.node.services.*
 import com.r3corda.core.node.services.testing.MockStorageService
 import com.r3corda.core.testing.MOCK_IDENTITY_SERVICE
 import com.r3corda.node.serialization.NodeClock
-import com.r3corda.node.services.api.Checkpoint
-import com.r3corda.node.services.api.CheckpointStorage
 import com.r3corda.node.services.api.MonitoringService
 import com.r3corda.node.services.api.ServiceHubInternal
 import com.r3corda.node.services.network.MockNetworkMapCache
@@ -15,23 +13,6 @@ import com.r3corda.node.services.network.NetworkMapService
 import com.r3corda.node.services.persistence.DataVendingService
 import com.r3corda.node.services.wallet.NodeWalletService
 import java.time.Clock
-import java.util.concurrent.ConcurrentLinkedQueue
-
-class MockCheckpointStorage : CheckpointStorage {
-
-    private val _checkpoints = ConcurrentLinkedQueue<Checkpoint>()
-    override val checkpoints: Iterable<Checkpoint>
-        get() = _checkpoints.toList()
-
-    override fun addCheckpoint(checkpoint: Checkpoint) {
-        _checkpoints.add(checkpoint)
-    }
-
-    override fun removeCheckpoint(checkpoint: Checkpoint) {
-        require(_checkpoints.remove(checkpoint))
-    }
-}
-
 
 class MockServices(
         customWallet: WalletService? = null,
diff --git a/node/src/test/kotlin/com/r3corda/node/services/PerFileCheckpointStorageTests.kt b/node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileCheckpointStorageTests.kt
similarity index 97%
rename from node/src/test/kotlin/com/r3corda/node/services/PerFileCheckpointStorageTests.kt
rename to node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileCheckpointStorageTests.kt
index c40302af59..93149ba6f5 100644
--- a/node/src/test/kotlin/com/r3corda/node/services/PerFileCheckpointStorageTests.kt
+++ b/node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileCheckpointStorageTests.kt
@@ -1,11 +1,10 @@
-package com.r3corda.node.services
+package com.r3corda.node.services.persistence
 
 import com.google.common.jimfs.Configuration.unix
 import com.google.common.jimfs.Jimfs
 import com.google.common.primitives.Ints
 import com.r3corda.core.serialization.SerializedBytes
 import com.r3corda.node.services.api.Checkpoint
-import com.r3corda.node.services.persistence.PerFileCheckpointStorage
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.Assertions.assertThatExceptionOfType
 import org.junit.After
diff --git a/node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorageTests.kt b/node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorageTests.kt
new file mode 100644
index 0000000000..d7a347c69a
--- /dev/null
+++ b/node/src/test/kotlin/com/r3corda/node/services/persistence/PerFileTransactionStorageTests.kt
@@ -0,0 +1,85 @@
+package com.r3corda.node.services.persistence
+
+import com.google.common.jimfs.Configuration.unix
+import com.google.common.jimfs.Jimfs
+import com.google.common.primitives.Ints
+import com.r3corda.core.contracts.SignedTransaction
+import com.r3corda.core.crypto.DigitalSignature
+import com.r3corda.core.crypto.NullPublicKey
+import com.r3corda.core.serialization.SerializedBytes
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import java.nio.file.Files
+
+class PerFileTransactionStorageTests {
+
+    val fileSystem = Jimfs.newFileSystem(unix())
+    val storeDir = fileSystem.getPath("store")
+    lateinit var transactionStorage: PerFileTransactionStorage
+
+    @Before
+    fun setUp() {
+        newTransactionStorage()
+    }
+
+    @After
+    fun cleanUp() {
+        fileSystem.close()
+    }
+
+    @Test
+    fun `empty store`() {
+        assertThat(transactionStorage.getTransaction(newTransaction().id)).isNull()
+        assertThat(transactionStorage.transactions).isEmpty()
+        newTransactionStorage()
+        assertThat(transactionStorage.transactions).isEmpty()
+    }
+
+    @Test
+    fun `one transaction`() {
+        val transaction = newTransaction()
+        transactionStorage.addTransaction(transaction)
+        assertTransactionIsRetrievable(transaction)
+        assertThat(transactionStorage.transactions).containsExactly(transaction)
+        newTransactionStorage()
+        assertTransactionIsRetrievable(transaction)
+        assertThat(transactionStorage.transactions).containsExactly(transaction)
+    }
+
+    @Test
+    fun `two transactions across restart`() {
+        val firstTransaction = newTransaction()
+        val secondTransaction = newTransaction()
+        transactionStorage.addTransaction(firstTransaction)
+        newTransactionStorage()
+        transactionStorage.addTransaction(secondTransaction)
+        assertTransactionIsRetrievable(firstTransaction)
+        assertTransactionIsRetrievable(secondTransaction)
+        assertThat(transactionStorage.transactions).containsOnly(firstTransaction, secondTransaction)
+    }
+
+    @Test
+    fun `non-transaction files are ignored`() {
+        val transactions = newTransaction()
+        transactionStorage.addTransaction(transactions)
+        Files.write(storeDir.resolve("random-non-tx-file"), "this is not a transaction!!".toByteArray())
+        newTransactionStorage()
+        assertThat(transactionStorage.transactions).containsExactly(transactions)
+    }
+
+    private fun newTransactionStorage() {
+        transactionStorage = PerFileTransactionStorage(storeDir)
+    }
+
+    private fun assertTransactionIsRetrievable(transaction: SignedTransaction) {
+        assertThat(transactionStorage.getTransaction(transaction.id)).isEqualTo(transaction)
+    }
+
+    private var txCount = 0
+    private fun newTransaction() = SignedTransaction(
+            SerializedBytes(Ints.toByteArray(++txCount)),
+            listOf(DigitalSignature.WithKey(NullPublicKey, ByteArray(1))))
+
+}
\ No newline at end of file