Neo4J server exception - fails to start

The server had been running fine and dandy but suddenly stopped. Tried restarting but that didn't help. This is what the log says: ``` 2015-02-18 15:07:58.092+0000 INFO [o.n.k.i.DiagnosticsManager]: --- SHUTDOWN diagnostics END --- 2015-02-18 15:07:58.336+0000 ERROR [o.n.s.CommunityBootstrapper]: Failed to start Neo Server on port [7474] org.neo4j.server.ServerStartupException: Starting Neo4j Server failed: Error starting org.neo4j.kernel.EmbeddedGraphDatabase, /var/lib/neo4j-community-2.1.4/data/graph.db at org.neo4j.server.AbstractNeoServer.start(AbstractNeoServer.java:226) ~[neo4j-server-2.1.4.jar:2.1.4] at org.neo4j.server.Bootstrapper.start(Bootstrapper.java:108) [neo4j-server-2.1.4.jar:2.1.4] at org.neo4j.server.Bootstrapper.main(Bootstrapper.java:62) [neo4j-server-2.1.4.jar:2.1.4] Caused by: java.lang.RuntimeException: Error starting org.neo4j.kernel.EmbeddedGraphDatabase, /var/lib/neo4j-community-2.1.4/data/graph.db at org.neo4j.kernel.InternalAbstractGraphDatabase.run(InternalAbstractGraphDatabase.java:366) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:59) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.impl.recovery.StoreRecoverer.recover(StoreRecoverer.java:123) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.server.preflight.PerformRecoveryIfNecessary.run(PerformRecoveryIfNecessary.java:65) ~[neo4j-server-2.1.4.jar:2.1.4] at org.neo4j.server.preflight.PreFlightTasks.run(PreFlightTasks.java:71) ~[neo4j-server-2.1.4.jar:2.1.4] at org.neo4j.server.AbstractNeoServer.runPreflightTasks(AbstractNeoServer.java:362) ~[neo4j-server-2.1.4.jar:2.1.4] at org.neo4j.server.AbstractNeoServer.start(AbstractNeoServer.java:159) ~[neo4j-server-2.1.4.jar:2.1.4] ... 2 common frames omitted Caused by: org.neo4j.kernel.lifecycle.LifecycleException: Component 'org.neo4j.kernel.StoreLockerLifecycleAdapter@7bd760a1' was successfully initialized, but failed to start. Please see attached cause exception. at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:513) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.lifecycle.LifeSupport.start(LifeSupport.java:115) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.InternalAbstractGraphDatabase.run(InternalAbstractGraphDatabase.java:343) ~[neo4j-kernel-2.1.4.jar:2.1.4] ... 8 common frames omitted Caused by: org.neo4j.kernel.StoreLockException: Unable to obtain lock on store lock file: /var/lib/neo4j-community-2.1.4/data/graph.db/store_lock. Please ensure no other process is using this database, and that the directory is writable (required even for read-only access) at org.neo4j.kernel.StoreLocker.checkLock(StoreLocker.java:82) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.StoreLockerLifecycleAdapter.start(StoreLockerLifecycleAdapter.java:44) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.lifecycle.LifeSupport$LifecycleInstance.start(LifeSupport.java:507) ~[neo4j-kernel-2.1.4.jar:2.1.4] ... 10 common frames omitted Caused by: java.io.IOException: Unable to lock org.neo4j.kernel.impl.nioneo.store.StoreFileChannel@c8925d7 at org.neo4j.kernel.impl.nioneo.store.FileLock.wrapFileChannelLock(FileLock.java:38) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.impl.nioneo.store.FileLock.getOsSpecificFileLock(FileLock.java:93) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.DefaultFileSystemAbstraction.tryLock(DefaultFileSystemAbstraction.java:93) ~[neo4j-kernel-2.1.4.jar:2.1.4] at org.neo4j.kernel.StoreLocker.checkLock(StoreLocker.java:74) ~[neo4j-kernel-2.1.4.jar:2.1.4] ... 12 common frames omitted ``` UPDATE Acted upon the advice given in the answer but unfortunately the server still doesn't start. neo4j start command has been waiting for server to start for the last 10 minutes: Using additional JVM arguments: -server -XX:+DisableExplicitGC -Dorg.neo4j.server.properties=conf/neo4j-server.properties -Djava.util.logging.config.file=conf/logging.properties -Dlog4j.configuration=file:conf/log4j.properties -XX:+UseConcMarkSweepGC -XX:+CMSClassUnloadingEnabled Starting Neo4j Server...WARNING: not changing user process [29578]... waiting for server to be ready......... The log file says: ``` 2015-02-18 15:50:09.958+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: [/var/lib/neo4j-community-2.1.4/data/graph.db/nioneo_logical.log.1] entries found=91485 lastEntryPos=5328191 2015-02-18 15:50:09.958+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: Opened logical log [/var/lib/neo4j-community-2.1.4/data/graph.db/nioneo_logical.log.1] version=8, lastTxId=513504 (recovered) 2015-02-18 15:50:09.959+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: XaResourceManager[nioneo_logical.log] sorting 0 xids 2015-02-18 15:50:09.997+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: XaResourceManager[nioneo_logical.log] checkRecoveryComplete 0 xids 2015-02-18 15:50:10.407+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.relationshiptypestore.db.names rebuild id generator, highId=35 defragged count=0 2015-02-18 15:50:10.490+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.labeltokenstore.db.names rebuild id generator, highId=17 defragged count=0 2015-02-18 15:50:10.571+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.labeltokenstore.db rebuild id generator, highId=16 defragged count=0 2015-02-18 15:50:10.653+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.propertystore.db.index.keys rebuild id generator, highId=49 defragged count=0 2015-02-18 15:50:10.776+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.propertystore.db.index rebuild id generator, highId=44 defragged count=0 2015-02-18 15:50:10.819+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.propertystore.db.strings rebuild id generator, highId=41 defragged count=0 2015-02-18 15:50:11.101+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.propertystore.db.arrays rebuild id generator, highId=7954 defragged count=0 2015-02-18 15:50:15.753+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.propertystore.db rebuild id generator, highId=212690 defragged count=0 2015-02-18 15:50:19.113+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.relationshipstore.db rebuild id generator, highId=234591 defragged count=0 2015-02-18 15:50:19.155+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.nodestore.db.labels rebuild id generator, highId=1 defragged count=0 2015-02-18 15:50:20.131+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.nodestore.db rebuild id generator, highId=46820 defragged count=0 2015-02-18 15:50:20.194+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.schemastore.db rebuild id generator, highId=5 defragged count=0 2015-02-18 15:50:20.300+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore.relationshipgroupstore.db rebuild id generator, highId=14508 defragged count=0 2015-02-18 15:50:20.423+0000 INFO [o.n.k.i.n.s.StoreFactory]: /var/lib/neo4j-community-2.1.4/data/graph.db/neostore rebuild id generator, highId=9 defragged count=0 2015-02-18 15:50:20.424+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: XaResourceManager[nioneo_logical.log] recovery completed. 2015-02-18 15:50:20.424+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: Recovery on log [/var/lib/neo4j-community-2.1.4/data/graph.db/nioneo_logical.log.1] completed. 2015-02-18 15:50:20.628+0000 INFO [o.n.k.i.t.TxManager]: TM opening log: /var/lib/neo4j-community-2.1.4/data/graph.db/tm_tx_log.2 2015-02-18 15:50:20.992+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: Non clean shutdown detected on log [/var/lib/neo4j-community-2.1.4/data/graph.db/index/lucene.log.1]. Recovery started ... 2015-02-18 15:50:20.992+0000 INFO [o.n.k.i.t.x.XaLogicalLog]: [/var/lib/neo4j-community-2.1.4/data/graph.db/index/lucene.log.1] logVersion=2 with committed tx=199234 ``` My server previously had around 50K nodes and 300K relationships. Is the server attempting to recover the data, and hence causing the delay in starting?