Maximize Operational Efficiency in a Tiered Storage Environment
W H I T E P A P E R : T E C H N I C A L Maximize Operational Efficiency in a Tiered Storage Environment Use Cases for Orchestrated Volume and Page-based Migration with Hitachi Tiered Storage Manager (HTSM) and Hitachi Dynamic Tiering (HDT) Orchestration By Manu Batra May 2012
2 Table of Contents Executive Summary 3 Introduction: Macro versus Micro Data Movement 4 Case 1. Nondisruptively Deploy Existing Application Data into Hitachi Dynamic Tiering Pools 4 Case 2. Hitachi Dynamic Tiering Pool Balancing: Move Volumes across HDT Pools 6 Case 3. Cyclic Resource Utilization 6 Case 4. Hitachi Dynamic Tiering Pool Rebalancing 7 Case 5. Reactive versus Proactive Movement of Data 8 Case 6. Hitachi Dynamic Tiering I/O Scheduling 8 Summary 10
3 Executive Summary Organizations can deploy page-based data movement for Hitachi Dynamic Tiering (HDT) and volume-based data movement by using Hitachi Tiered Storage Manager (HTSM) to create an opti- mal and efficient data layout for any application. The 2 can be used together to efficiently share resources across multiple applications and maximize storage resource utilization. This white paper offers use cases that describe scenarios in which HTSM and HDT can work together to maximize the benefits of tiered storage management. The use cases also emphasize the fact that the 2 products together provide a powerful solution for optimiz- ing storage system layout.
4 Introduction: Macro versus Micro Data Movement Page-based data movement delivers an automated, nondisruptive layout optimization in a storage pool based on input/output (I/O) intensity. Hitachi Tiered Storage Manager volume-based data movement delivers volume movement across internal and external storage tiers. Both types of data movement are needed within a data center. The following are key scenarios that describe the differences. Case 1. Nondisruptively Deploy Existing Application Data into Hitachi Dynamic Tiering Pools As a part of a Hitachi Dynamic Tiering deployment, existing application volumes need to be moved into the HDT pools. Hitachi Tiered Storage Manager provides nondisruptive volume migration tech- nology that enables volume migration across internal and external storage systems. The nondisrup- tive nature of the migration provides organizations with the flexibility to deploy without waiting for an application or data center maintenance window. It can drastically improve efficiency of the HDT deployment. HTSM v7.1.1 has eliminated the need to create migration groups. A new migration wizard enables migration sources to be selected from logical group constructs, hosts or free-form volume filters based on configuration and performance data. The performance data allows users to easily identify hot and cold spots. The system auto-selects target volumes (a user override option is also provided) and indicates expected performance (improve or decrease) after migration. Once the migration tasks are created, the system provides an estimated completion time and allows the migration task to be executed immediately or scheduled to be completed at a later date and time (see Figures 1 and 2).
5 Figure 1. Migration Wizard Source Volume Selection: Choose source volumes based on logical groups, hosts, or performance or configuration metrics. Figure 2. Source and Target Volume Mapping: Migration wizard indicates (by arrows) performance impact on the volume based on the target volume characteristics.
6 Case 2. Hitachi Dynamic Tiering Pool Balancing: Move Volumes across HDT Pools As application storage capacity grows over time, Hitachi Dynamic Tiering pools will reach a maxi- mum either in capacity or I/O. This will require either a capacity increase of the HDT pool or a migra- tion of the application volumes to another HDT pool with available resources to balance the pool utilization. Hitachi Tiered Storage Manager will enable users to nondisruptively rebalance the pools by moving application volumes across the pools. HTSM also provides specific reports to highlight the pool utilization (see Figure 3). These reports can quickly highlight whether the pools are reaching a maximum and whether capacity or I/O threshold have been exceeded. Figure 3. Data Mobility Pool Summary Report Case 3. Cyclic Resource Utilization Certain applications have cyclic I/O profiles (see Figure 4). For example, a quarterly billing applica- tion, which experiences low I/O traffic for 11 weeks in quarter, has very high I/O activity during the last week of the month when customer billing happens.
7 Using Hitachi Tiered Storage Manager volume-based mobility, the volumes can be nondisruptively moved across storage pools of different compositions [pools with solid state disk (SSD), SAS or SATA drives to pools with SAS or SATA drives] without impacting application availability. These would be very effective for storage service providers and customers with cyclic I/O patterns. Figure 4. Hitachi Tiered Storage Manager: Volume-based Mobility for Cyclical Applications Case 4. Hitachi Dynamic Tiering Pool Rebalancing Hitachi Dynamic Tiering provisioning has thresholds for overprovisioning. Once thresholds have been exceeded, volumes may be moved, nondisruptively, to pools with more free space. Hitachi Tiered Storage Manager allows this rebalancing to happen nondisruptively. It also provides reports to quickly identify pools that will need rebalancing (see Figure 5). Figure 5. Data Mobility Pool Configuration Report with Thresholds
8 Case 5. Reactive versus Proactive Movement of Data Hitachi Dynamic Tiering page movement is reactive in nature; i.e., pages are moved in reaction to observed I/O patterns. There may be cases where organizations have predictive periods of high activity for certain application volumes. Hitachi Tiered Storage Manager volume-based movement can proactively or temporarily move such volumes to HDT pools appropriate for high I/O activity; then, after the activity has subsided, the volume can be moved back to its original HDT pool (see Figure 6). This can help organizations achieve a high level of operation efficiency without assigning permanent Tier 1 storage resources to application that may not need them. It also allows resource sharing across various applications. Figure 6. Cyclic Movement of Data across Pools for Macro Optimization Case 6. Hitachi Dynamic Tiering I/O Scheduling ■■Hitachi Dynamic Tiering is designed to react to I/O density by moving high I/O activity pages to higher storage tier disks. ■■By default, HDT is constantly monitoring I/O and making decisions to move data within the pool.
9 ■■However, data center I/O cycles are not linear. There may be maintenance, backup and other non-performance-sensitive time periods. ■■Hitachi Tiered Storage Manager mobility manager will enable HDT to adjust or schedule monitor- ing windows to work around non-performance-sensitive time periods (see Figure 7). Figure 7. Hitachi Dynamic Tiering Monitoring: Capability can be disabled for backup and maintenance hours of the week. An example of the HDT Monitoring Schedule Template appears in Figure 8. It depicts scheduling periods: ■■8:00 a.m. through 16:00 (4 p.m.) at 2-hour cycles, Monday through Friday ■■16:00 (4 p.m.) through 8:00 a.m. at 4-hour cycles, Monday through Friday ■■Saturday and Sunday using 12-hour cycles.
10 Figure 8. Hitachi Dynamic Tiering: I/O Monitoring Schedule Sample Summary Hitachi Tiered Storage Manager volume migration and Hitachi Dynamic Tiering page tiering together can maximize storage resource utilization and optimize the storage layout for applications across a Hitachi tiered storage environment. Hitachi Tiered Storage Manager and Hitachi Dynamic Tiering complement each other by helping organizations to easily and efficiently realize the following data mobility use cases: ■■Nondisruptively deploying existing application data into HDT pools ■■HDT pool balancing: moving volumes across pools ■■Cyclic resource utilization ■■Hitachi Dynamic Tiering pool rebalancing ■■Reactive versus proactive movement of data To maximize the benefits of a tiered storage management solution, it is suggested that Hitachi Tiered Storage Manager and Hitachi Dynamic Tiering be used together. Using both products pro- vides a complete solution for optimizing macro and micro data layout across Hitachi tiered storage environments.