All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic,mechanical, photocopying, recording or otherwise, without the prior written permission of the publisher. Scyld ClusterWare, the Highly Scyld logo, and the Penguin Computing logo are trademarks of Penguin Computing, Inc. All other trademarks and copyrights referred to are the property of their respective owners.