Enhancing Oracle VM Business Continuity Using Dell Compellent Live Volume Wendy Chen, Roger Lopez, and Josh Raw Dell Product Group February 2013
This document is for informational purposes only and may contain typographical errors and technical inaccuracies. The content is provided as is, without express or implied warranties of any kind. 2013 Dell Inc. All rights reserved. Dell and its affiliates cannot be responsible for errors or omissions in typography or photography. Dell, the Dell logo, Compellent, PowerConnect, and PowerEdge are trademarks of Dell Inc. Intel and Xeon are registered trademarks of Intel Corporation in the U.S. and other countries. Oracle is a registered trademark of the Oracle Corporation. Brocade is a registered trademark of Brocade Communications Systems, Inc. Microsoft, Windows, and Windows Server are either trademarks or registered trademarks of Microsoft Corporation in the United States and/or other countries. Other trademarks and trade names may be used in this document to refer to either the entities claiming the marks and names or their products. Dell disclaims proprietary interest in the marks and names of others. February 2013 Rev 1.0 Page ii
Contents Executive summary... 2 Introduction... 3 Dell solutions for Oracle... 3 Technology overview... 3 Dynamic Storage Migration with Live Volume... 5 Oracle VM... 7 Oracle VM Live Migration... 8 Oracle VM with Dell Compellent Live Volume... 8 Test configurations and results... 10 Oracle VM Live Migration in a single data center... 10 Oracle VM Live Migration between two data centers... 13 Summary... 16 References... 17 Figures Figure 1. New generation of Dell Compellent storage hardware... 4 Figure 2. Dell Compellent Storage Center 6... 5 Figure 3. Dell Compellent Live Volume... 6 Figure 4. Oracle VM architecture (Source: Oracle)... 7 Figure 5. Oracle VM live migration... 8 Figure 6. Integrating Oracle VM with Dell Compellent Live Volume... 9 Figure 7. Oracle VM environment in one data center at a single site... 10 Figure 8. Oracle live migration of VM... 11 Figure 9. Reconfigure Linux DM Multipath to change primary and standby data access path... 12 Figure 10. Live Volume automatic role swapping... 13 Figure 11. Oracle VM environment between two data centers... 14 Figure 12. Oracle VM live migration between data centers... 15 Page 1
Executive summary Traditional data recovery tasks related to planned outages and impending events are common for IT administrators in many organizations. Typical IT data center maintenance such as software upgrades, hardware maintenance, and configuration changes is required to ensure the efficiency of data center systems. Proper maintenance can prevent unplanned downtime in the long term; however, routine maintenance can potentially interrupt service availability, causing business disruption and lost revenue. Severe predictable natural disasters, such as floods and hurricanes, can also cause business disruption for prolonged periods of time. When these events occur, it is often necessary for administrators to perform manual data recovery tasks. Some level of automation can be achieved through scripts closely tailored to specific vendor solutions, but these often require expensive onsite consulting services. Dell Compellent Live Volume, an innovative software feature for the Dell Compellent Storage Center Storage Area Network (SAN), delivers dynamic business continuity to keep applications online and data accessible during planned downtime. Live Volume provides a new layer of virtualization that enables a physical server or virtual machine (VM) to share a virtual storage volume between two Storage Center SANs in a semi-synchronous configuration. When preparing for planned maintenance or anticipating another type of outage or disruption, administrators can quickly and easily designate primary status to the secondary system on demand in either the same data center or another local data center ensuring continued availability without disrupting user access to data. Live Volume also helps organizations balance workloads on demand without disruption. With dynamic horizontal movement of data between systems, administrators can easily migrate data sets to a new array, optimize I/O performance, maximize resource utilization, and accommodate demand spikes caused by end-of-quarter financials, retail promotions, or other shortterm periodic events. Live Volume works in the Oracle VM environment, automatically moving storage volumes in sync with VM movement between hosts. An important complement to remote replication and server virtualization, Live Volume can help organizations reach a new level of availability and flexibility. Storage is no longer tied to one production SAN, but rather virtualized between two SANs, with semisynchronous replication for continuous data protection, regardless of physical location data is written first to the volume on the primary array, then replicated to the other instance of the volume on the secondary array. Page 2
Introduction Dell Compellent Live Volume acts as a storage hypervisor, concurrently mapping one volume to two Compellent arrays to shift volumes between systems for continuous data access. Live Volume is supported by multiple hypervisors, including VMware, Microsoft Hyper-V, and Citrix XenServer. It allows seamless movement of storage volumes in sync with virtual machine movements between hosts. This paper validates Live Volume integration with an Oracle VM. The team performed a series of tests to validate how Live Volume interacts with OLTP workloads in the Oracle VM environment. Test results prove that Live Volume can be effectively utilized in the Oracle VM environment for zero-down time system maintenance, non-disruptive system migration, and on-demand workload distribution. These capabilities empower IT administrators to address challenges beyond traditional reactive data recovery into proactive business continuity. Dell solutions for Oracle Dell solutions for Oracle products simplify operations, improve usability, and provide cost-effective scalability. Dell Configurations for Oracle In-depth testing of Oracle configurations for high-demand solutions, including documentation and tools that help simplify deployment Integrated Solution Management Standards-based management of Dell solutions for Oracle that can lower operational costs through integrated hardware and software deployment, monitoring, and updating Oracle Licensing Licensing options to simplify purchase Dell Enterprise Support and Infrastructure Services for Oracle Planning, deployment, and maintenance of Dell solutions for Oracle database tools For more information about Dell Solutions for Oracle, visit www.dell.com/oracle. Technology overview The Dell Compellent Storage Center Storage Area Network (SAN) provides a highly efficient and flexible foundation for enterprise and the cloud. Dell Compellent storage features an innovative Dell Fluid Data architecture to put the right data in the right place at the right time. This Fluid Data architecture enables the storage system to dynamically adapt to the changing business environment. Figure 1 depicts the latest generation of the Dell Compellent storage hardware. Page 3
Figure 1. New generation of Dell Compellent storage hardware SC8000 is the latest-generation Dell Compellent Storage Center controller platform. Leveraging twelve generations of Dell hardware design experience, SC8000 controller offers: Built-in intelligence, agility, and automation No fork-lift upgrade and perpetual licensing Fibre Channel (4Gb, 8Gb), iscsi (1Gb, 10Gb), and FCoE (10Gb) simultaneous front-end connectivity support SAS (6Gb, 3Gb) and Fibre Channel (2Gb, 4Gb, 8Gb) back-end connectivity support Improved performance and enhanced memory, advanced power efficiency, and improved diagnostics over previous generation systems SC200 and SC220 are the latest generation of Storage Center expansion enclosures. Also based on the Dell PowerEdge 12 th Generation server hardware design, the SC200 and SC220 offer support for: Solid-State Drive (SSD), SAS, and Fibre Channel technologies RAID 0, 5, 6, RAID 10, RAID 10 DMMultiple RAID levels on the same storage tier within an array Dell Compellent software uses a 64-bit operating system called Storage Center. Storage Center version 6.2 is the latest release. Key features are shown in Figure 2: Automated tired storage automatically moves data blocks among different storage tiers, which are defined by the disk drive categories. For example, the fastest and most expensive disk drives form the top tiers, and the slower performance and lower cost drives form the lower tiers. Storage Center is capable of capturing data block usage patterns, and the automated tiered storage uses this data to determine whether and when data blocks should be moved from one tier to another. Automated tiered storage can improve application performance and lower cost at the same time, as highly accessed data is moved to top storage tiers and less frequently accessed data is moved to lower storage tiers. Page 4
Thin provisioning helps eliminate the need for pre-allocating storage space by using storage space only when data is written to the disk. This feature helps lower the cost of storage. Dynamic storage migration is a Live Volume feature that acts as a storage hypervisor, actively mapping one volume to two Compellent arrays at the same time. This allows volumes to be shifted between systems for continuous data access. With Live Volume, data is not physically bound to any particular array or data center. Compellent fluid data architecture provides true storage virtualization. There are no constraints on where data can reside, because data is not confined to the traditional disk group concept. Data blocks can be moved without limitation to a tier with a particular drive type or performance level, or to a particular RAID level within a storage tier. Continuous snapshot and thin replication offer capabilities to make quick data copies, which can be leveraged as backup recovery and disaster recovery solutions. Figure 2. Dell Compellent Storage Center 6 Dynamic Storage Migration with Live Volume Live Volume is a software option for Dell Compellent Storage Center that builds on fluid data architecture (see Figure 3). Live Volume enables non-disruptive data access and migration of data between two Storage Center implementations for both physical and virtual environments. Page 5
Figure 3. Dell Compellent Live Volume Live Volume includes a pair of semi-synchronous replicating volumes: a primary Live Volume and a secondary Live Volume. Data is written first to the primary Live Volume, then immediately replicated to the secondary Live Volume. A Live Volume can be accessed through either Storage Center participating in a Live Volume replication; however, all read and write activity for a Live Volume occurs on the Storage Center hosting the primary Live Volume. If a server is accessing the data through the secondary Live Volume Storage Center, all read and write activities are proxied over the replication link to the primary Live Volume Storage Center. There are many use cases for which administrators can utilize Live Volume to provide continuous data access during planned maintenance and disaster avoidance. Virtualized storage follows virtualized server. Live Volume automatically detects when a Virtual Machine (VM) moves from one physical server to another. Immediately after the detection of the VM migration, Live Volume automatically swaps the roles between the primary Live Volume and the secondary Live Volume, and automatically reverses the replication direction. On-demand workload distribution. Live Volume enables users to eliminate hot spots between the two Storage Center implementations and offload I/O burdens from one storage array to another, without disrupting application and data availability. Zero-downtime maintenance. By anticipating planned maintenance or other impending outages, administrators can easily designate the secondary Live Volume Storage Center as the primary role. All I/O is migrated to the secondary Storage Center non-disruptively. Following the event, administrators can reverse the live migration process and resume normal operations. Non-disruptive system migration. Live Volume provides administrators with a way to migrate data to an all new system while applications remain online. During migration, Live Volume transparently moves volumes from the existing array to the new array while applications continue to run as usual. For more information about Dell Compellent Live Volume, visit http://www.compellent.com/products/software/live-volume.aspx. Page 6
Oracle VM Oracle VM is server virtualization software based on Xen architecture. Oracle VM can be deployed on industry standard x86 servers, and it supports Windows, Linux, and Oracle Solaris as the guest operating systems running inside the virtual machine. As shown in the Oracle VM architecture diagram in Figure 4, Oracle VM consists of three components: Oracle VM Server is based on the Xen kernel and underlying hypervisor technology that provides the ability to host guest VMs. Oracle VM Manager is a web-based management console used to simplify the use of Oracle VM feature sets by providing a graphical user interface (GUI) that allows users to point and click to interact with the Oracle VM Server to create, clone, and migrate virtual machines, among other features. Oracle VM agent is an application installed within the Oracle VM Server. It enables communication between the Oracle VM Server and Oracle VM Manager for management of an Oracle VM environment. Figure 4. Oracle VM architecture (Source: Oracle) Oracle supports two types of virtual machines: fully virtualized and paravirtualized. Fully-virtualized VMs are unmodified guest operating systems that have no knowledge of the underlying hardware. As a result, fully-virtualized environments allow for ease in areas such as portability and migration, but can suffer a performance penalty. In contrast, paravirtualized guest operating systems (OS) have modifications to the guest operating that make them aware that they are running on a virtual machine, which in turn provides near native performance levels. It is recommended to use paravirtualized guest OS virtual machines. To learn more about Dell s best practice recommendations on Oracle VM deployment and configuration, visit http://en.community.dell.com/techcenter/enterprisesolutions/w/oracle_solutions/1429.current-release.aspx. Page 7
Oracle VM Live Migration One of the key features sets found within Oracle VM is the ability to live migrate a virtual machine hosted on an Oracle VM Server within a server pool to another server located within the same Oracle VM server pool with no downtime. This is important, because it provides the flexibility of moving virtual machines based on workload requirements and the ability to plan maintenance on an existing Oracle VM Server, if required. Live migration has two key requirements: Shared storage at the same mount points for all Oracle VM Servers within the server pool Shared Oracle VM Server (OVS) Repository used across all Oracle VM Servers within the server pool Figure 5 illustrates the Oracle VM live migration feature. Live migration enables secure migration of a running VM from one physical server to another server within the same server pool, without causing interruptions to virtual machines. Live migration is useful to minimize downtime during planned outages by proactively moving virtual machines to available servers in the same server pool. Figure 5. Oracle VM live migration Oracle VM with Dell Compellent Live Volume Dell Compellent Live Volume complements Oracle VM by adding a new layer of storage virtualization. With Live Volume, a physical or virtual server is simultaneously mapped to two instances of the same storage volume on two distinct Dell Compellent storage systems. Though the server sees only a single Page 8
consistent volume, Live Volume enables administrators to seamlessly move storage workloads from one storage system to another on demand. Figure 6. Integrating Oracle VM with Dell Compellent Live Volume As shown in Figure 6, Dell Compellent Live Volume can be effectively integrated with Oracle VM. Together, they offer several notable benefits: Extending Oracle VM virtual environment outside a data center. With the traditional storage configuration, an Oracle VM server pool consists of a shared storage (Figure 5). When implementing Oracle VM in conjunction with Compellent Live Volume, a second storage system is included in a server pool (Figure 6). The two storage arrays can be located in the same data center or in two distinct data centers, which provides the foundation for extending an Oracle VM virtual environment outside a single data center. If the two data centers are located in separate sites, the application requirements will dictate the latency and bandwidth required between the sites. Typically dark fiber connectivity is used to meet latency requirements but connection media may vary. Business continuity from planned server, storage, or data center maintenance. Oracle VM live migration eliminates outages from planned downtime of server maintenance by moving virtual machines off of servers that are undergoing planned maintenance. Compellent Live Volume enables all data to be moved non-disruptively between two storage systems. By utilizing Live Volume, storage maintenance activities can be done without any downtime. When jointly implementing Oracle VM and Compellent Live Volume in two different data centers, downtime from data center maintenance activities can be avoided by moving virtual machines to the server and storage that reside in the other data center. Page 9
Disaster avoidance in anticipation of predictable natural disasters. To prepare for an impending natural disaster event, virtual machines can be moved to a remote data center before the local data center has an outage. Test configurations and results Dell engineers conducted a series of integration tests between Oracle VM and Dell Compellent Live Volume. The following sections describe the test tools, configurations and results. Oracle VM Live Migration in a single data center Two test configurations were set up. In the first configuration, the Oracle VM environment resides in a single data center. Figure 7. Oracle VM environment in one data center at a single site As shown in Figure 7, the single site Oracle VM environment consists of the following components: An Oracle VM server pool with two PowerEdge R720 servers running Oracle VM 3.1. Oracle VM guest virtual machine running Oracle Enterprise Linux 6 Update 2 x86_64, and hosting an Oracle 11g Release 2 One Node Real Application Cluster (RAC) database version 11.2.0.3.0 inside the virtual machine. Seven pairs of Dell Compellent Live Volumes, including one pair of Live Volume for the Oracle VM server repository file, one pair of Live Volume for the cluster heart beat file, and five pairs of Live Volumes for the Oracle database data, residing on two Dell Compellent Storage Centers. The primary Live Volumes should be initially configured in a Compellent SC40 Storage Center implementation, and the secondary Live Volumes initially configured in a Compellent SC8000 Storage Center implementation. Page 10
Each R720 server in the server pool mapped to the seven primary Live Volumes initially so that I/O sent to the data path to the primary Live Volume. Client connections to the Oracle database from Quest Benchmark Factory TPC-C. To validate the integration between Oracle VM and Compellent Live Volumes, Dell engineers performed an Oracle VM live migration test on the configuration in Figure 7. The virtual machine that hosted the Oracle database instance was migrated from one R720 server to the other R720 server in the server pool. Instead of moving an idle database instance, Quest Benchmark Factory TPC-C was used to simulate active client transactions against the database during live migration. Benchmark Factory TPC- C is a load-generating utility that simulates OLTP users and transactions on a database for a given number of users. During the entire testing process, active client read/write transactions were simulated against the database in the virtual machine from the Quest Benchmark Factory TPC-C. The live migration test consisted of the following steps. 1. Executed live migration of the virtual machine from Oracle VM Manager to move the virtual machine from one R720 server to the other as shown in Figure 8. Figure 8. Oracle live migration of VM 2. Reconfigured volume mapping so that each R720 server mapped to the secondary Live Volume as shown in Figure 9. The reconfiguration of volume mapping causes a brief interruption to database availability. Page 11
Figure 9. access path Reconfigure Linux DM Multipath to change primary and standby data 3. At this point, Compellent Live Volume was able to detect that primary access to the Live Volumes was from the secondary Storage Center, so it automatically swapped the roles of the primary and the secondary Live Volume pairs. This is illustrated in Figure 10. Page 12
Figure 10. Live Volume automatic role swapping Oracle VM Live Migration between two data centers In the second configuration, the Oracle VM environment resides between two data centers as depicted in Figure 11. Page 13
Figure 11. Oracle VM environment between two data centers The configuration consists of the following components: An Oracle VM server pool with two PowerEdge R720 servers running Oracle VM 3.1 Oracle VM guest virtual machine running Oracle Enterprise Linux 6 Update 2 x86_64, and hosting an Oracle 11g Release 2 One Node Real Application Cluster (RAC) database version 11.2.0.3.0 inside the virtual machine Seven pairs of Dell Compellent Live Volumes, including one pair of Live Volume for the an Oracle VM server repository file, one pair of Live Volume for the cluster heart beat file, and five pairs of Live Volumes for the Oracle database physical data, residing on two Dell Compellent Storage Centers. The primary Live Volumes were initially configured in a Compellent SC40 Storage Center; the secondary Live Volumes were initially configured in a Compellent SC8000 Storage Center. The seven primary Live Volumes mapped to the R720 server in one data center; the seven secondary Live Volumes mapped to the other R720 server in the other data center. Client connections to the Oracle database from Quest Benchmark Factory TPC-C. Oracle live migration was also performed on the configuration in Figure 11. Again, the entire test process was performed while Benchmark Factory generated active transactions against the database instance. Testing consisted of the following steps: 1. Executed live migration to move virtual machine from the R720 in one data center to the other R720 in the other data center as illustrated in Figure 12. Page 14
Figure 12. Oracle VM live migration between data centers 2. Following the VM move, Compellent was able to detect that I/O came from the secondary Live Volumes; then, it automatically swapped the primary role and the secondary role of the Live Volume pairs as shown in Figure 13. Page 15
It is important to note that the entire testing process did not disrupt database availability or client transactions from the Benchmark Factory. The database remained available and served I/O to the active client connections. Summary Integrated with Oracle VM, Dell Compellent Live Volume improves business continuity by seamlessly moving data between two storage arrays and breaking virtual machine dependency on physical storage systems. By combining storage and virtualization technologies, businesses can extend the Oracle VM environment outside a single data center to enhance business continuity while performing planned server, storage, and data center maintenance, and to avoid service disruptions during predictable natural disasters. This paper demonstrates these benefits through testing live migration of two Oracle VM environments one for a single data center and another for two data centers connected via a Wide Area Network (WAN). It also discusses best practices for configuring DM multipath when integrating Oracle VM and Dell Compellent Live Volume. To learn more about Dell Oracle solutions, visit www.dell.com/oracle or contact your Dell representative for up-to-date information on Dell servers, storage, and services for Oracle solutions. Page 16
References 1. Compellent Best Practices for Storage Center and Live Volume, a Dell technical white paper 2. Deliver Dynamic Business Continuity for the Enterprise with Dell Compellent Live Volume, a Dell technical white paper http://www.davenportgroup.com/_asset/48vzg6/cml-whitepaper_oct-2011.pdf 3. Compellent Live Volume Datasheet http://www.compellent.com/~/media/www/files/datasheets/ds_live_volume.ashx Page 17