我不太确定我在这里做错了什么。
我让neo4j数据库2.1.5在linux下工作正常（除了缓慢）。所以我尝试upgrade到2.2版本。
这是我采取的步骤：
1. stop 2.1.5
2. copy from 2.1.5/data/graph.db to 2.2/data/graph.db
3. allow-store-upgrade=true
4. start 2.2 by using command ./bin/neo4j start
但是，我一直收到这个错误：
Failed to start within 120 seconds.Neo4j Server may have failed to start, please check the logs.
我已经有一段时间了。任何建议我在这里做错了什么？
编辑：
这是我的messages.log文件的结尾：
Caused by: org.neo4j.kernel.impl.storemigration.StoreUpgrader$UpgradingStoreVersionNotFoundException: 'neostore.nodestore.db' does not contain a store version, please ensure that the original database was shut down in a clean state.
at org.neo4j.kernel.impl.storemigration.UpgradableDatabase.checkUpgradeable(UpgradableDatabase.java:82) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.impl.storemigration.StoreMigrator.needsMigration(StoreMigrator.java:159) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.impl.storemigration.StoreUpgrader.getParticipantsEagerToMigrate(StoreUpgrader.java:259) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.impl.storemigration.StoreUpgrader.migrateIfNeeded(StoreUpgrader.java:134) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.NeoStoreDataSource.upgradeStore(NeoStoreDataSource.java:556) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.NeoStoreDataSource.start(NeoStoreDataSource.java:466) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:507) ~[neo4j-kernel-2.2.0-M02.jar:2.2.0-M02]
... 13 common frames omitted