Storage management is crucial to the overall health of IT infrastructure. The popularity of virtualization and big data has made storage systems a critical component of any IT environment, and storage performance issues can contribute to a negative impact on the end user through application performance problems, such as delays or downtime.
Storage Monitoring Challenges
Diagnosing the root cause of performance bottlenecks can be challenging when multiple tiers of a technology stack are dependent on data storage devices and systems. It can be difficult to initially assess whether a slowdown is related to storage or another system component.
If the performance issue is related to the network storage environment, additional diagnosis may be necessary to pinpoint the exact problem due to the complexities of storage resources.
Diagnosing Storage Performance Problems
Performance issues are often blamed on storage resources, and although it's tempting to upgrade a storage system to improve speed, application performance should be diagnosed prior to purchasing new equipment. Review the following metrics to assess the overall health of your application before examining storage infrastructure:
CPU utilization: If CPU utilization is lower than 50 percent, there may be a storage performance issue. A low CPU utilization indicates that the CPU is waiting on something such as user response or storage. If CPU utilization is 50 percent or higher, continue troubleshooting elements outside of your storage environment to pinpoint the root cause of the problem.
Queue depth: Queue depth is another valuable clue in evaluating storage performance. Queue depth demonstrates that an application is making requests of storage, and any depth hints at a possible performance problem. However, anything greater than three or four warrants further investigation, and a queue depth that hits triple digits points to an issue with storage performance. Some storage management tools detail queue depth by storage adapter, disk volume, or storage controller which makes it easier to pinpoint the root cause of an issue.
Latency: Latency measures the system's response time when processing requests. Latency can be attributed to high data fragmentation or if a database is accessing a large cache of records. Comparing queue depth and latency can indicate whether you're dealing with a storage issue or an issue with seeks.
IOPS: Last but not least, the combined I/O per second can serve as a key performance metric. IOPS refers to the transfer time of files onto or off of the drive, and how many read/write operations can be achieved in a second. A steady IOPS metric can signify that your storage infrastructure is under strain and may require an upgrade.
Solid-state drives (SSDs) are often a helpful option when it comes to mitigating performance problems, and can prove to be more cost-effective than purchasing more mechanical drives.
Reviewing performance metrics through storage monitoring can help you evaluate which storage devices are the most appropriate for your system's circumstances.
Storage Monitoring Benefits
Storage performance monitoring tools provide notifications and alerting when a slowdown happens, and are capable of tracking performance metrics across all storage arrays to assist with monitoring and diagnosis.
You are able to get to the root cause of issues quickly and resolve costly performance problems with real-time visibility into inbound and outbound throughput, protocol operations and performance metrics throughout your organization.
You can also analyze and alert based on storage performance trends over time, and use this information to proactively tune performance to improve resource efficiency and optimize end-user experience.
The most effective management software provides deep visibility into every facet of storage infrastructure, such as LUNs, physical disks, caches, host ports, controllers, fiber channel switches, and enclosures while also tracking systems such as disk usage, directory size, file count, and file size. The depth of coverage combined with access to historical trends and baselines simplifies analysis by correlating storage performance with application and network performance to help better define the root cause of an issue.
Storage monitoring can help evaluate:
Storage capacity needs to ensure adequate resources for optimal performance
The health and performance of device ports, LUNs, controllers, physical disks and disk groups
The density of I/O traffic on disk groups
Slowdowns occurring on physical disks during read/write actions
Which external host handles the highest number of requests
If the disk array has a queue of requests awaiting processing
Storage monitoring software provides a level of visibility that allows administrators to take a proactive approach to predicting, diagnosing, and resolving issues within the storage environment, which ultimately improves the end user experience through better application performance.