Technical White Paper for the WORM Issue 01 Release Date 2009-12-01 Huawei Symantec Technologies Co., Ltd.
Copyright Chengdu Huawei Symantec Technologies CO., Ltd. 2010. All rights reserved. No part of this document may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Symantec Technologies Co., Ltd. Trademarks and Permissions and other Huawei Symantec icons are trademarks of Chengdu Huawei Symantec Technologies CO., Ltd. All other trademarks and trade names mentioned in this document are the property of their respective holders. Note The purchased products, services and features are stipulated by the commercial contract between Chengdu Huawei Symantec Technologies CO., Ltd. and the customer. All or partial products, services and features described in this document may not be within the purchased scope or the usage scope. Unless otherwise agreed by the contract, all statements, information, and recommendations in this document are provided "AS IS" without warranties, guarantees or representations of any kind, either express or implied. The information in this document is subject to change without notice. Every effort has been made in the preparation of this document to ensure accuracy of the contents, but all statements, information, and recommendations in this document do not constitute the warranty of any kind, express or implied. Huawei Symantec Technologies Co., Ltd. Address: Building 1 The West Zone Science Park of UESTC, No.88, Tianchen Road Chengdu, 611731 P.R.China Website: Email: http://www.huaweisymantec.com support@huaweisymantec.com Telephone: 86-400-888-2333 Fax: 86-28-87897555 Page 2 of 18
Update History Date Issue Description Prepared By 2010-05-12 1.0 Initial release. Cong Yang Page 3 of 18
Contents 1 Executive Summary... 7 2 Introduction... 9 3 Solution... 11 3.1 Introduction to WORM... 11 3.2 Principle of WORM... 11 3.3 WORM LUN vs. Common LUN... 12 4 Experience... 15 5 Conclusion... 17 6 Acronyms and Abbreviations... 18 Page 4 of 18
Figures Figure 3-1 Process of WORM... 11 Figure 3-2 Data read and write on a common LUN... 12 Figure 3-3 Data read and write on a WORM LUN... 12 Page 5 of 18
Tables Table 3-1 Common LUN vs. WORM LUN... 13 Table 6-1 Acronyms and abbreviations related to the WORM... 18 Page 6 of 18
1 Executive Summary This document describes the principle, process, and scenarios of the Write Once Read Many (WORM) technology for the Oceanspace series storage system. In addition, this document introduces the technological superiority and regulatory compliance of Huawei Symantec WORM technology. Page 7 of 18
2 Introduction In the countries outside China, public sectors, financial institutions, and medical organizations are forbidden by law to delete or overwrite their business documents at will. For example, once electronic medicine charts are archived, they cannot be deleted or modified. In comparison, there is little law in China that regulates data storage. As the law system has been improving and more and more China companies have started their exploration in oversea markets, data archiving will be a focus. Under this background, the storage technologies that incorporate the WORM function have emerged as a solution to data archiving. Page 9 of 18
3 Solution 3.1 Introduction to WORM WORM is realized through the combination of hardware and software. Once data is written onto the storage media with the WORM technology embedded, the data cannot be modified or deleted. WORM secures the backup of special and mission-critical data. 3.2 Principle of WORM The principle of WORM is the judgment of WORM LUNs on the array side. If a common LUN is specified as a WORM LUN, this LUN is read-only. Figure 3-1 shows the process of WORM. Figure 3-1 Process of WORM Page 11 of 18
1. The host sends the read/write I/O to the array. 2. The LUN to be read or written is judged for a WORM LUN on the Target (TGT) layer of the array. 3. If the LUN is a WORM LUN, the read I/O is successfully sent and the read data is returned to the host. But the write I/O cannot be sent and an error code is returned to the host. The user can set a LUN as a WORM LUN for a period (days). In this protection period, data on this LUN cannot be modified or deleted. Before the period expires, the user can prolong rather than shorten the period. When the protection expires, the user can manually set the WORM LUN back to a common LUN. Then, all restrictions originally on the WORM LUN disappear. The protection period ranges from 1 day to 60 years (60 x 365 days). 3.3 WORM LUN vs. Common LUN For the host's data reading and writing: Data on a common LUN can be read and written, whereas data on a WORM LUN is read-only. Figure 3-2 and Figure 3-3 show the details: Figure 3-2 Data read and write on a common LUN Figure 3-3 Data read and write on a WORM LUN Page 12 of 18
For their value-added features: A WORM LUN is used as a source LUN rather than a destination LUN. And there are restrictions for a WORM LUN working as a source LUN, as listed in Table 3-1. Table 3-1 Common LUN vs. WORM LUN LUN Value-added Features Virtual Snapshot Remote Replication LUN Copy LUN Extension Common LUN Snapshot and rollback Synchronous and asynchronous replication; Source LUN and destination LUN No restriction. Failover WORM LUN Snapshot; Rollback not supported Synchronous and asynchronous replication; Failover not supported Source LUN; destination LUN not supported WORM cannot be enabled before the implementation of LUN extension. Page 13 of 18
4 Experience WORM mainly applies to the fields where archived data cannot be modified or destroyed. The demand for data protection is derived from regulatory compliance or organizations' individual concerns. The WORM technology protects data on the storage media against loss or tamper and is suitable for the long-term retention of mission-critical data. In addition, the WORM technology caters for regulatory compliance for data storage. Page 15 of 18
5 Conclusion The WORM technology for the Oceanspace series storage system is easy to master and has broad market opportunities. This technology applies to the applications that require read-only protection for important data. Huawei Symantec WORM technology complies with the industry standards and rules, such as the Sarbanes-Oxley Act, HIPAA, US-SEC Rule 17a-4, and Gramm-Leach-Bliley Act. Page 17 of 18
6 Acronyms and Abbreviations Table 6-1 Acronyms and abbreviations related to the WORM Acronym WORM LUN TGT Full Spelling Write Once Read Many Logical Unit Number Target Page 18 of 18