Softek Storage Solutions Inc. recently added Performance Tuner to its Storage Manager Enterprise Storage Resource Management (ESRM) suite of products, which also includes Space Optimizer and SANView. The new Performance Tuner product is designed to identify existing, as well as potential, storage bottlenecks and component failures. Performance Tuner should bolster Softek's efforts to keep pace with rivals such as CA's BrightStor Storage Resource Manager, Tivoli Storage Resource Management and Veritas' CommandCentral. But Performance Tuner adds a new capability not commonly found in other SRM suites.
SRM can yield significant benefits: storage utilization improvement, reduced planned and unplanned downtime, and better storage procurement practices and prices.
A growing number of organizations are implementing service-level agreements (SLAs) with end users and suppliers alike. Performance Tuner lets IT organizations measure and monitor storage systems, from the aggregate to the finite, to assess compliance with SLAs and solve performance problems. But SRM tools tend to be so monolithic and complex that they become shelfware over time. There is a need for SRM tools that:
- Are easy enough to use
- Perform essential functions without excessive overhead
- Avoid problems rather than simply providing a postmortem on past problems
|Single screen summarizes data:|
Performance Tuner's easy-to-navigate interface offers a single-screen view of service index, throughput and responsiveness.
Our tests were based on these criteria.
Atesting environment for an enterprise SRM product requires a sufficiently diverse configuration to exercise the product's capabilities. Our test setup was provided by the Storage Networking Industry Association (SNIA), a Colorado Springs, CO, industry group dedicated to advancing storage technology and deployment. In the SNIA lab, we used three Microsoft Windows XP systems, one Windows 2003 system and a Sun Solaris server. All the Windows servers had Emulex LP10000 host bus adapters (HBAs) connected to an IBM Enterprise Storage Server model F20 via a Brocade SilkWorm 2800 Fibre Channel switch. Additionally, the Sun server had 50GB of direct-attached storage that was being monitored. While relatively modest, this configuration included most of the typical elements found in larger SANs. We also used Iometer, an open-source tool used to induce a sequential access or random access workload on storage systems for testing purposes.
Softek recommends that ESRM and Performance Tuner be installed on a standalone Windows 2000 or Windows 2003 server. Agents must also be installed on each managed server. The agent controls a small local database that stores captured information. Installing an individual agent is quick and easy, but installation across large server farms with hundreds or thousands of servers could involve significant effort. Nevertheless, this architecture is consistent with other products in the category.
Softek also recommends that professional services be engaged for the initial installation. This is sound advice; even with a Softek engineer on site, our total installation spanned nearly three days, although some of that time was spent waiting for materials. SRM systems have complex interdependencies, and grappling with them can eat up a storage administrator's time. For example, we ran into an inconsistency between the Brocade switch and Windows Server 2003 that required a substitution with Windows Server 2000. We should point out that the desirability of professional services assistance is consistent with our experiences using other SRM products.
Performance Tuner is displayed in the Storage Manager console as a separate tab with its own menu items (see "Single screen summarizes data"). The GUI is intuitive, easy to use and lets an administrator build performance data queries without having to know SQL. It should be noted that included runtime versions of SQL Server and MySQL run on the main server. Performance Tuner has a rich set of graphing tools, allowing data and graphs to be exported for further manipulation or inclusion in other documents.
|Graphic View of Performance:|
Performance Tuner lets you select and consolidate performance data to create throughput graphs.
The main drawback to Performance Tuner in a storage area network (SAN) environment is its dependency on the separate SANView product to get an overall performance summary picture. Performance Tuner is excellent for gathering information about data access times, which is a key metric for SLAs. To view information about HBA and switch port performance, however, SANView must also be installed. These two product views need to be better integrated. For example, viewing alerts and SAN hardware status is accomplished via two separate screens, one in SANView for the overall status of the SAN hardware and one in Performance Tuner for the data access metrics. Ultimately, Softek consolidates the information into a concise view by allowing the graphing of HBAand switch performance directly with the data access metrics (see "Graphic view of performance").
Environment and performance
Our test configuration did not challenge the scalability of Storage Manager. Softek boasts an installation scaling to 500 million files, and others with more than 300 servers each. Softek says the agent's impact on each managed server is generally less than 5% of CPU resources. A bigger issue is the time needed to perform a full environment scan. In this respect, the critical factor is the number of files to be scanned; a large number of small files takes longer than a small number of large files. Organizations with a high file count should be prepared for this process to take the better part of a weekend. The server scans occur in parallel, however, so it's really the largest server file count that determines the total scan time.
After the baseline data is gathered, Space Optimizer gathers and reports incremental sets of data from the agents to the main server. These small sets can be collected in a matter of minutes or hours. Although an administrator can set the data collection process for any interval, once per day is typically sufficient.
SRM tools can easily drown an administrator in data. Performance Tuner's primary strength is its ability to summarize data access statistics into three key, easy-to-monitor metrics: throughput I/O, service index and responsiveness. Similar to a person's heart rate, blood pressure and temperature, these three items provide a quick picture of a storage system's health. Throughput is measured by read/write rates in KB/sec; the service index is the ratio of cached data requests to data requests queued to be read from the disk; and responsiveness is the latency delay in obtaining data. Although Softek provides general guidelines for these metrics (such as a service ratio greater than 70% is a best practice), IT organizations should develop their own data over time. The data that's collected by Performance Tuner for graphing and trend analysis can be used to easily identify deviations from the norm and project future system performance.
Of course, a variety of other statistics can also be monitored, four in particular: Windows cache, physical disk, processor and system times. Each of these includes four to 20 different metrics. History, profile and correlation graphing functions are provided so that an administrator can look back in time, match data access metrics to physical HBA and switch port metrics, and do some predictive analysis. Alerts that trigger when pre-set thresholds are exceeded are easy to set, and can generate SNMP traps, e-mails or displays on the application's alerts screen.
Breadth of features
Performance Tuner offers a solid starting point for storage performance monitoring, upon which Softek can continue to build. Although its name suggests it can provide remedial measures, it offers the features that are most critical to SLA monitoring and management without an onerous administrative overhead.
Softek's biggest challenge will be supporting the myriad devices found in ITenvironments. Even in our modest test configuration, we ran into the problem with the Brocade switch due to an API that was not supported by Windows 2003 Server. Of course, it isn't necessarily required that every component in a SAN be supported, but IT organizations should verify their own configurations prior to purchase with a trial of the system.
Rating the product
Here's how Performance Tuner stacks up against our ideal:
- Easy enough to use – After a fairly involved setup, Performance Tuner is simple enough that a junior-level administrator can manage and monitor the product. The powerful graphing and reporting functions effectively summarize a large amount of information into easily understood graphics. In this regard, we would rate Performance Tuner as "very good."
- Performs essential functions without excessive overhead – By providing the three base metrics as the macro view of performance, Softek has crossed our threshold for providing actionable information without obscuring it with irrelevant data. Thus, we give the product an "excellent" rating for this aspect.
- Proactively avoids problems – As a component of ESRM, data gathered by Performance Tuner can be manipulated to create trending and forecast models. As a monitoring and reporting product, Performance Tuner doesn't take remedial action for identified problems. This is the key limitation of most SRM products, so we can't single out Performance Tuner for blame. Other components of Storage Manager, however, do offer some automated capabilities. For this criterion, we give Performance Tuner an "average" rating.
Bearing in mind the adage, "If you can't measure it, you can't manage it," it's surprising that so few IT organizations have deployed an SRM tool. Other performance monitoring methods are available, although mainly from a database or application perspective. Hardware-based monitoring tools are available that deliver precise throughput data, but they don't take remedial action either. Moreover, it's not practical to physically install a device in every data path.
Softek's product offers a unique combination of component-level data gathering that can't be achieved with an application monitor or most SRM products, and a breadth of data gathering and reporting that can't be achieved with a hardware device. The system as configured for our test included Space Optimizer, SANView and Performance Tuner, and has a list price of $58,054, which includes one year of 24x7 technical support.
IT organizations seeking to improve their storage environment performance should begin with an SRM tool, and the Softek suite is a worthy addition to any shortlist of candidates.