When restarting the server the build nodes constantly switch between online and offline. Log file contains the following

Jul 24, 2014 8:08:24 AM WARNING hudson.node_monitors.AbstractAsyncNodeMonitorDescriptor monitor

Failed to monitor auto-tst-dev-w1 for Free Disk Space
java.nio.channels.ClosedChannelException
at sun.nio.ch.SocketChannelImpl.ensureWriteOpen(SocketChannelImpl.java:249)
at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:440)
at hudson.remoting.SocketChannelStream$2.write(SocketChannelStream.java:62)
at java.nio.channels.Channels.writeFullyImpl(Channels.java:78)
at java.nio.channels.Channels.writeFully(Channels.java:101)
at java.nio.channels.Channels.access$000(Channels.java:61)
at java.nio.channels.Channels$1.write(Channels.java:174)
at java.io.ObjectOutputStream$BlockDataOutputStream.drain(ObjectOutputStream.java:1857)
at java.io.ObjectOutputStream$BlockDataOutputStream.setBlockDataMode(ObjectOutputStream.java:1766)
at java.io.ObjectOutputStream.writeFatalException(ObjectOutputStream.java:1560)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:349)
at hudson.remoting.Command.writeTo(Command.java:83)
at hudson.remoting.ClassicCommandTransport.write(ClassicCommandTransport.java:51)
at hudson.remoting.Channel.send(Channel.java:545)
at hudson.remoting.Request.callAsync(Request.java:208)
at hudson.remoting.Channel.callAsync(Channel.java:766)
at hudson.node_monitors.AbstractAsyncNodeMonitorDescriptor.monitor(AbstractAsyncNodeMonitorDescriptor.java:76)
at hudson.node_monitors.AbstractNodeMonitorDescriptor$Record.run(AbstractNodeMonitorDescriptor.java:280)

Jul 24, 2014 8:08:24 AM WARNING hudson.node_monitors.AbstractAsyncNodeMonitorDescriptor monitor

Failed to monitor auto-tst-prd-w1 for Free Disk Space
hudson.remoting.ChannelClosedException: channel is already closed
at hudson.remoting.Channel.send(Channel.java:541)
at hudson.remoting.Request.callAsync(Request.java:208)
at hudson.remoting.Channel.callAsync(Channel.java:766)
at hudson.node_monitors.AbstractAsyncNodeMonitorDescriptor.monitor(AbstractAsyncNodeMonitorDescriptor.java:76)
at hudson.node_monitors.AbstractNodeMonitorDescriptor$Record.run(AbstractNodeMonitorDescriptor.java:280)
Caused by: java.nio.channels.AsynchronousCloseException
at java.nio.channels.spi.AbstractInterruptibleChannel.end(AbstractInterruptibleChannel.java:205)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:386)
at hudson.remoting.SocketChannelStream$1.read(SocketChannelStream.java:33)
at sun.nio.ch.ChannelInputStream.read(ChannelInputStream.java:65)
at sun.nio.ch.ChannelInputStream.read(ChannelInputStream.java:109)
at sun.nio.ch.ChannelInputStream.read(ChannelInputStream.java:103)
at java.io.InputStream.read(InputStream.java:101)
at sun.nio.ch.ChannelInputStream.read(ChannelInputStream.java:81)
at hudson.remoting.FlightRecorderInputStream.read(FlightRecorderInputStream.java:82)
at java.io.ObjectInputStream$PeekInputStream.peek(ObjectInputStream.java:2291)
at java.io.ObjectInputStream$BlockDataInputStream.peek(ObjectInputStream.java:2584)
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2594)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1316)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370)
at hudson.remoting.Command.readFrom(Command.java:92)
at hudson.remoting.ClassicCommandTransport.read(ClassicCommandTransport.java:70)
at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:48)