How to Locate a Storage Bottleneck

Few Sysadmins really understand what’s happening in the storage interface of their systems, yet there’s a lot of talk about SSDs with wide-ranging IOPS figures along with case studies of how these have helped solve system slowdowns.  The big question is: “How do you determine what your storage bottleneck is, and even whether or not one exists at all?”

Tom Coughlin and I discovered a very low level of understanding of this issue when we performed the IOPS survey late last year that we documented in our report: How Many IOPS do You Really Need?  A disconcerting number of respondents gave replies that contradicted themselves or that made little, if any, sense.

SNIA (the Storage Networking Industry Association), through its Solid State Storage Initiative (SSSI)  has recently produced a free download that can help solve that problem.  This organization’s new Workload I/O Capture Program, or WIOCP, is a simple tool that captures software applications’ I/O activity by gathering statistics on workloads at the user level (IOPS, MB/s, response times queue depths, etc.)

The WIOCP helps users to identify “Hot Spots” where storage performance is creating bottlenecks.  Users can collect (and optionally display in real time) information reflecting their current environment and operations with the security of a tool delivered with digital authentication for their protection.

The collected I/O metrics will provide information useful to evaluate an SSD in a system environment.

This program collects statistics from a wide range of applications, and these can be used with the SNIA’s SSS Performance Test Specification to help users determine which SSD should  perform best for them.

The WIOCP software is a safe and thoroughly-tested tool which runs unobtrusively in the background to constantly capture a large set of SSD and HDD I/O metrics that are useful to both the computer user and to SNIA.

Users simply enter the drive letters for those drives for which I/O operations metrics are to be collected.   The program does not record anything that might be sensitive, including details of your actual workload (for example, files you’ve accessed.)   Results are presented in clear and accessible report formats.

SNIA has released this tool with the goal of improving SSD performance.  The organization encourages users to help the association by sharing the real-use statistics this program collects with SNIA by uploading their results to the SNIA website.

Using this information SNIA member companies will be able to improve the performance of their solid state storage solutions, including SSDs and flash storage arrays.

The WIOCP provides unique, raw information that can be analyzed by SNIA’s Technical Work Groups (TWGs) including the IOTTA TWG to gain insights into workload characteristics, key performance metrics, and SSD design tradeoffs.

The collected data from all participants will be aggregated and publicly available for download and analysis. No personally identifiable information is collected – participants will benefit from this information pool without comprising their privacy or confidentiality.

The program is very easy to download and install.  Click HERE and use the “Download Key Code”: SSSI52kd9A8Z.

The WIOCP tool will be delivered to your system with a unique digital signature.  The tool only takes a few minutes to download and initialize, after which users can return to the task at hand!

If you have any questions or comments you may contact: SSSI_TechDev-Chair@SNIA.org