• Monitor system performance using the Unisphere GUI

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    Monitor system performance using the Unisphere GUI

    Working with performance metrics in the Unisphere GUI

    You can analyze system performance in Unisphere by viewing and interacting with line charts that display historical and real-time performance metrics. Metrics collection on the storage system is enabled by default.

    The system automatically allocates space for storing collected metrics, whether or not metrics collection is enabled.
    Historical metrics

    Historical metrics display data collected within a preset or customized time range. With historical metrics charts, you can:

    • Compare changes in performance across multiple metrics, such as network traffic, bandwidth, and throughput.
    • Analyze data at both the aggregate and detail levels:
      • Aggregated performance metrics information is initially displayed in line charts, enabling you to quickly determine whether there are any high-level performance issues.
      • Once you open a line chart, you can drill down to the detailed data by applying breakdown categories to the displayed data.
    • Export the data of selected metrics to a .csv file. The exported values reflect the metric's filtered state.

    Line charts for historical metrics typically display 150 - 300 samples. Within a line chart, different time ranges correlate to specific sampling intervals, as shown in the following table:

    Table 1. Time ranges and associated sampling intervals
    Time range setting
    Sampling interval
    Last 1 Hour
    1 minute
    Last 4 Hours
    1 minute
    Last 12 Hours
    5 minutes
    Last 24 Hours
    5 minutes
    Last 7 Days
    1 hour
    Last 30 Days
    4 hours
    Last 90 Days
    4 hours
    Custom
    Varies based on the length of the range. If the range is more than one week, the sampling interval is 4 hours.

    If you select a preset time range for a metric (such as 1 Week), but the amount of available data is less than the associated display interval for that preset, the system tries to display the data using the next smallest available interval. This behavior can also occur when you page back and forth through time.

    For example, suppose you select the Cache Read Hit IOPS metric and the 1 Week preset. The system tries to display the metric data in one hour intervals. If there is:

    • Less than one hour's worth of metric data, but more than five minutes' worth of metric data, the system displays the data using five minute intervals.
    • Less than one minute's worth of metric data, the system defaults to the most granular sample size possible, while keeping the legibility of the graph intact.
    Real-time metrics

    Real-time metrics display data collected during the current session, over a maximum time range of 15 minutes. The session ends when you navigate away from the current tab and restarts when you navigate back to the tab. You can display up to four real-time metrics charts at a time on a dashboard.

    With real-time metrics charts, you can:

    • Compare changes in performance across multiple metrics, such as network traffic, bandwidth, and throughput.
    • Analyze data at the aggregated level using line charts, to quickly determine whether there are any performance issues.

    The sampling interval for real-time metrics is every 5 seconds.

    About line charts

    A line chart initially displays aggregated information for one performance metric, such as LUN Bandwidth. The line chart shows the metric's value along the y-axis against the time range on the x-axis. When you hover over a data point on a line chart, a tool tip displays the time, date, and measurement associated with that data point.

    System line charts display all information across all like resources in the storage system. For example, the System-IO File System Bandwidth metric displays the total amount of file system I/O requests, in KB/s, across all file systems in the storage system. Resource line charts display all information for the selected resource objects. For example, the File System Bandwidth metric displays the total amount of file system I/O requests, in KB/s, for the selected file systems.

    Depending on the metric, each line chart aggregates data using one of the following calculations:

    Table 2. Calculations used for aggregating data
    Calculation
    Description
    Sum
    Total of the measurements for each target object instance. For example, the LUN Bandwidth metric adds together the amount of I/O traffic handled by each LUN.
    Average
    Sum of a set of numerical measurements divided by the number of measurements in the set. For example, the system uses the following formula to calculate the CPU Utilization metric, which is calculated as a percentage: 
                                  [(Percentage of processing cycles used by SP1) + (Percentage of processing cycles used by SP2) / 2]
    Weighted average
    Average that gives more weight to the objects with the highest contribution to the metric. The storage system uses the following formula to calculate a weighted average: 
                                  [(m1 * w1) + (m2 * w2) + (m3 * w3) / (w1 + w2 + w3)]
    where:
    • m1 is the metric for object 1, m2 is the metric for object 2, and so forth.
    • w1 is the weight for object 1, w2 is the weight for object 2, and so forth.
    For example, the storage system uses the following formula to calculate the LUN IO Size metric: 
                                  [((LUN1 I/O size) * (Number of LUN1 I/Os)) + ((LUN2 I/O size * (Number of LUN2 I/Os)) + ((LUN3 I/O size) * (Number of LUN3 I/Os))/ (Number of LUN1 I/Os) + (Number of LUN2 I/Os) + (Number of LUN3 I/Os)]
    In this example, the LUNs with the highest number of I/Os have the highest weighting.
    Ratio
    Relative size of two values. For example, the FAST Cache Dirty Ratio metric measures the ratio of dirty pages to total pages in the FAST Cache.

    For information about the calculation used by a particular metric, see the help topic for that metric.

    View historical performance metrics

    Procedure
    1. Under System, select Performance.
    2. Select the historical metrics dashboard for the system for which you created a performance metrics display.
    3. For each system dashboard, you can define the time range of the values displayed for all the metric line charts on that dashboard. The default time range is Last 1 hour. Alternatively, select one of the other time range values.
      The time range selections are enabled only if Unisphere has data spanning that time range.
    4. For a custom time range, select Custom and choose the start and end dates and times of the charts displayed. Click OK.
    5. To drill down into the data displayed in the line chart, you can breakdown the data displayed into individual lines that show the categories and contributors that provide data to the performance metric. Choose among the breakdown categories available for a particular metric.
      Each contributor displays as a different color line in the chart and is identified in the legend. You can quickly remove and add each contributor by clicking on its name in the legend. Use the breakdown display to determine if one contributor is adding to the aggregated total more than another contributor as well as analyze how a contributor's activity increases or decreases at a particular time.
    6. Hover over a data point in the chart to display the date, time, and measurement associated with that data point. Gaps in metric data collection are displayed as gaps in the line chart.

    View real-time performance metrics

    Procedure
    1. Under System, select Performance.
    2. Select the real-time metrics dashboard for the system for which you created a performance metrics display.

    Add performance metrics charts

    Use Add Charts to select the performance metric charts to be displayed on each dashboard tab.
    Procedure
    1. Under System, select Performance.
    2. To display charts for historical metrics, select Historical Charts > Add Charts.
    3. To display real-time metrics, select Real-time Charts > Add Charts.
    4. Select the resource type for which you want to display metrics.
    5. From the list of available metrics for that resource type, select the metrics you want to display. If applicable, select the objects for which you want to display metrics.
    6. Select Generate Charts to save your selections, and then select Close.
    7. Optionally, repeat these steps to select other resource types or metrics.
    Results
    There is no limit to the number of historical metric charts you can display on each dashboard tab, but you can only display up to four real-time metric charts. Newly added charts display at the top of the display; you can drag and drop charts to different positions.

    Available historical performance metrics

    The following historical performance metrics are available in the Unisphere GUI. For more information about a particular metric, including its breakdown categories, select the link in the Metric column.

    Resource category
    Metric
    System - Cache
    Cache Dirty Size
    Cache Read Hit IOPS
    Cache Read Miss IOPS
    Cache Write Hit IOPS
    Cache Write Miss IOPS
    FAST Cache Dirty Ratio
    System - IO
    CIFS Bandwidth
    CIFS I/O Size
    CIFS IOPS
    File System Bandwidth
    File System I/O Size
    File System IOPS
    LUN Bandwidth
    LUN I/O Size
    LUN IOPS
    LUN Queue Length
    LUN Response Time
    NFS Bandwidth
    NFS I/O Size
    NFS IOPS
    VVOL Datastore Bandwidth
    VVOL Datastore IOPs
    VVol Datastore Response Time
    System - Resources
    CPU Utilization
    Drive Bandwidth
    Drive IOPS
    Ethernet Bandwidth
    Ethernet Packets
    Fibre Channel Bandwidth
    Fibre Channel Requests/Second
    iSCSI Bandwidth
    iSCSI Requests/Second
    LUN
    Bandwidth
    I/O Size
    IOPS
    Queue Length
    Response Time
    File System
    Bandwidth
    I/O Size
    IOPS
    VVol Datastore
    Bandwidth
    IOPs
    Response Time
    Fibre Channel Port
    Bandwidth
    Requests/Second
    iSCSI Interface
    Bandwidth
    Requests/Second
    Ethernet Port
    Bandwidth
    Packets
    Drive
    Bandwidth
    IOPS
    Queue Length
    Response Time
    Service Time
    Tenant
    Bandwidth

    Available real-time performance metrics

    The following real-time performance metrics are available in the Unisphere GUI.

    Resource category
    Metric
    Description
    System - Resources
    CPU Utilization
    Total amount of processing cycles, as a percentage, across all cores in the storage system SPs.
    LUN
    Bandwidth Read, Write, or Total
    Amount of LUN read, write, or total I/O requests, in KB/s, for the selected LUNs.
    I/O Size Read or Write
    Average size of LUN read or write I/O requests, in KB, across all LUNs in the storage system. Calculated as a weighted average, which gives more weight to the LUNs with the highest number of I/O requests.
    IOPS Read, Write, or Total
    Number of LUN read, write, or total I/O requests, in I/O per second, for the selected LUNs.
    Queue Length
    Average number of LUN I/O requests in the system queue, in counts per second, for the selected LUNs.
    Response Time
    Average time spent completing LUN I/O requests, in microseconds, for the selected LUNs in the storage system. Calculated as a weighted average, which gives more weight to the LUNs with the highest number of I/O requests.
    File System
    Bandwidth Read or Write
    Amount of file system read or write I/O requests, in KB/s, for the selected file systems.
    I/O Size Read or Write
    Average size of file system read or write I/O requests, in KB, across all file systems in the storage system. Calculated as a weighted average, which gives more weight to the file systems with the highest number of I/O requests.
    IOPS Read or Write
    Number of file system read or write I/O requests, in I/O per second, for the selected file systems.
    Fibre Channel Port
    Bandwidth Read or Write
    Amount of Fibre Channel read or write I/O requests, in KB/s, for the selected Storage Processors and associated Fibre Channel ports.
    Requests/Second Read or Write
    Number of Fibre Channel read or write I/O requests, in I/O per second, for the selected Storage Processors and associated Fibre Channel ports.
    iSCSI Interface
    Bandwidth Read or Write
    Amount of iSCSI read or write I/O requests, in KB/s, for the selected iSCSI interfaces.
    Requests/Second Read or Write
    Number of iSCSI read or write I/O requests, in I/O per second, for the selected iSCSI interfaces.
    Ethernet Port
    Bandwidth Read or Write
    Amount of iSCSI read or write I/O requests, in KB/s, for the selected iSCSI interfaces.
    Packets Read or Write
    Number of Ethernet read or write packets per second, for the selected Storage Processors and associated Ethernet ports.
    Drive
    Bandwidth Read or Write
    Amount of drive read or write I/O requests, in KB/s, for the selected drives used in provisioned storage.
    IOPS Read, Write, or Total
    Number of drive read, write, or total I/O requests, in I/O per second, for the selected drives used in provisioned storage.
    Queue Length
    Average number of drive I/O requests in the system queue, in counts per second, for the selected drives used in provisioned storage. Calculated as a weighted average, which gives more weight to the drives with the highest number of I/O requests.
    Response Time
    Average time spent completing drive I/O requests, in microseconds, for the selected drives used in provisioned storage, including time spent in the queue. Calculated as a weighted average, which gives more weight to the drives with the highest number of I/O requests.
    The assumptions the system makes when calculating the average drive response time may not hold true for bursty traffic.
    Service Time
    Average time spent completing drive I/O requests, in microseconds, for the selected drives used in provisioned storage, not including time spent in the queue. Calculated as a weighted average, which gives more weight to the drives with the highest number of I/O requests.