last error before crash

2013-05-22 16:21:53 [SEVERE] java.lang.OutOfMemoryError: unable to create new native thread
2013-05-22 16:21:53 [SEVERE] 	at java.lang.Thread.start0(Native Method)
2013-05-22 16:21:53 [SEVERE] 	at java.lang.Thread.start(Thread.java:691)
2013-05-22 16:21:53 [SEVERE] 	at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:949)
2013-05-22 16:21:53 [SEVERE] 	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1371)
2013-05-22 16:21:53 [SEVERE] 	at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:357)
2013-05-22 16:21:53 [SEVERE] 	at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:509)
2013-05-22 16:21:53 [SEVERE] 	at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:227)
2013-05-22 16:21:53 [SEVERE] 	at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:472)
2013-05-22 16:21:53 [SEVERE] 	at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:404)
2013-05-22 16:21:53 [SEVERE] 	at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
2013-05-22 16:21:53 [SEVERE] Encountered an unexpected exception OutOfMemoryError
java.lang.OutOfMemoryError: unable to create new native thread
	at java.lang.Thread.start0(Native Method)
	at java.lang.Thread.start(Thread.java:691)
	at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:949)
	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1371)
	at org.bukkit.craftbukkit.v1_5_R3.scheduler.CraftScheduler.mainThreadHeartbeat(CraftScheduler.java:357)
	at net.minecraft.server.v1_5_R3.MinecraftServer.r(MinecraftServer.java:509)
	at net.minecraft.server.v1_5_R3.DedicatedServer.r(DedicatedServer.java:227)
	at net.minecraft.server.v1_5_R3.MinecraftServer.q(MinecraftServer.java:472)
	at net.minecraft.server.v1_5_R3.MinecraftServer.run(MinecraftServer.java:404)
	at net.minecraft.server.v1_5_R3.ThreadServerApplication.run(SourceFile:573)
2013-05-22 16:21:53 [SEVERE] This crash report has been saved to: /home/pve/server/./crash-reports/crash-2013-05-22_16.21.53-server.txt