arrow_back_ios

Main Menu

See All Software See All Instruments See All Transducers See All Vibration Testing Equipment See All Electroacoustics See All Acoustic End-of-Line Test Systems See All Academy See All Resource Center See All Applications See All Industries See All Services See All Support See All Our Business See All Our History See All Global Presence
arrow_back_ios

Main Menu

See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All DAQ Software See All Drivers & API See All Utility See All Vibration Control See All High Precision and Calibration Systems See All DAQ Systems See All S&V Hand-held Devices See All Industrial Electronics See All Power Analyzer See All S&V Signal Conditioner See All Acoustic See All Current and Voltage Sensors See All Displacement See All Force sensors See All Load Cells See All Pressure See All Strain Gauges See All Temperature Sensors See All Torque Sensors See All Vibration See All Accessories for Vibration Testing Equipment See All Vibration Controllers See All Measurement Exciters See All Modal Exciters See All Power Amplifiers See All LDS Shaker Systems See All Test Solutions See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All Training Courses See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All BKSV Worldwide Contacts
arrow_back_ios

Main Menu

See All API See All Microphone Cartridges See All Microphone Sets See All Microphone Pre-amplifiers See All Sound Sources See All Acoustic Calibrators See All Special Microphones See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All Piezoelectric Charge Accelerometers See All Piezoelectric CCLD (IEPE) accelerometers See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Dynamic Weighing See All Vehicle Electrification See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

Reliability Analysis of a Storage Cluster System

This example is based on the example shown in Figure 8 of the article "Determining the Availability and Reliability of Storage Configurations" by Santosh Shetty, August 2002, as posted on Dell's website.

Example

 

Consider a "high-availability" cluster with a reliability block diagram (RBD), as shown next.

Figure 1: Storage Cluster System

Assume the following life distributions and parameters for the components: (Note that this example, unlike the original article, assumes no repair of failed components.)

 

  • Server: Exponential with mean = 45,753 hours
  • Switch: Exponential with mean = 255,358 hours
  • HBA: Exponential with mean = 252,550 hours
  • Controller: Exponential with mean = 68,961 hours

 

The objective of the analysis is to study the reliability of the system.

Analysis

 

Step 1: Create the RBD of the system in BlockSim, and then use the given information to configure the universal reliability definitions (URDs) of each block. For example, the following picture shows the Block Properties window of Server1. The inset shows the Model Wizard, which allows you to define the failure model of the block. The URDs of the other blocks can be configured in a similar manner.

Figure 2: Block Properties Window of Server1 and Model Wizard (inset)

Step 2: Once the URDs have been configured, analyze the diagram and obtain the system reliability equation of the system, as shown next. In this equation, each R is the reliability (1-cdf) function of the item. As an example, RServer2 is the reliability function of Server 2.

Figure 3: System Reliability Equation of the Storage Cluster System

Step 3: Generate system level plots to see more information about the system. The next two charts are component reliability importance plots at t = 8544 hr. Both plots (a tableau area plot and a bar chart) illustrate the same concept; that is, the higher the importance of the component, the higher its effect on system reliability.

Figure 4: Static Reliability Importance - Tableau Area Chart
Figure 5: Static Reliability Importance - Bar Chart

As you can see, the servers in this configuration are the most critical component, while the hubs are the least critical.

 

The following pictures show additional plots.

Figure 6: RI vs. Time Plot
Figure 7: System Reliability Plot
Figure 8: System Failure Rate Plot
Figure 9: System pdf plot

Step 4: Use BlockSim's Analytical Quick Calculation Pad (QCP) to obtain some of the most frequently requested reliability results. For example, the MTTF (mean time to failure) of the system is about 42,135 hours, as shown next.

Figure 10: Analytical QCP