Help
Table Of Contents
- Dell EMC Storage Systems Online Help for the metro node appliance
- Contents
- Figures
- Welcome
- Using the GUI
- Configuring GUI default settings
- Using storage hierarchy maps
- Viewing system status
- Monitoring the system
- Performance
- The Performance Monitoring dashboard
- Viewing a chart
- Modifying a dashboard layout
- Creating a custom dashboard
- Removing a chart
- Moving a chart
- Back-end Bandwidth Chart
- Back-end Throughput chart
- Back-end Errors chart
- Back-end Latency chart
- CPU utilization chart
- Heap Usage chart
- Front-end Queue Depth chart
- Front-end Bandwidth chart
- Front-end Latency chart
- Front-end Throughput chart
- Front-end Aborts chart
- Write Latency Delta chart
- WAN Port Performance chart
- WAN Latency chart
- Rebuild Status dashboard
- Virtual Volumes dashboard
- Front End Ports dashboard
- System Health
- Performance
- Provisioning storage
- Guide
- Provisioning from storage volumes
- Provision Job properties
- Distributed storage
- Storage arrays
- Storage volumes
- Devices
- About devices
- Using the Devices view
- The Create Devices wizard
- The Add Local/Remote Mirror wizards
- Viewing the status of IO to a device
- Creating a device
- Renaming a device
- Deleting a device
- Mirroring a device
- Device status
- Device component properties
- Device properties
- Distributed device properties
- Add capacity to virtual volumes
- Extent properties
- Extents
- Distributed devices
- About distributed devices
- The Distributed Devices view
- The Create Distributed Device from Claimed Storage Volumes wizard
- Distributed device rule sets
- Changing the rule set for a distributed device
- Creating a distributed device
- Deleting a distributed device
- Renaming a distributed device
- Distributed Device status
- Virtual volumes
- About virtual volumes
- The Virtual Volumes view
- The Distributed Virtual Volumes view
- Creating a virtual volume
- About virtual volume expansion
- Expanding a virtual volume using storage volumes
- Enabling or disabling remote access for a volume
- Manually assigning LUN numbers to volumes
- Deleting a volume
- Renaming a volume
- Tearing down a volume
- Virtual Volume status
- Pool properties
- Virtual volume properties
- Show ITLs dialog box
- Logical unit properties
- ALUA Support field values
- Visibility field values
- Extent or Device mobility job properties
- Metro node port properties
- Storage array properties
- Storage view properties
- Storage volume properties
- Create Virtual Volumes dialog box
- Consistency group
- About consistency groups
- Using the Consistency Groups view
- Distributed Consistency Groups view
- Create Consistency Group wizard
- Types of consistency groups
- Creating a consistency group
- Adding a volume to a consistency group
- Removing a volume from a consistency group
- Deleting a consistency group
- Consistency Group status
- Consistency group properties
- Step 1: Select or create a consistency group for the virtual volume
- Step 1: Create a consistency group
- Step 2: Select volume options
- Step 3: Select a storage pool
- Step 3: Select a pool for each mirror on the second cluster
- Step 3: Select a pool for each mirror in the cluster
- Step3: Create thin virtual volumes
- Select a storage view for the virtual volume(s) (optional)
- Step 5: Review your selections
- Step 6: View results
- Step 2: Select volume options
- Step 2: Select volume options
- Step 3: Select a storage volume to create the virtual volume
- Step 3: Select a source and target storage volume
- Step 3: Create thin volumes
- Step 3: Select a target storage volume on the remote cluster
- Step 3: Select target storage on the remote cluster
- Step 6: View results
- Show Logical Units
- Exporting storage
- Initiators and metro node ports
- Storage views
- About storage views
- Using the Storage Views screen
- The Create Storage View wizard
- Creating a storage view
- Deleting a storage view
- Renaming a storage view
- Adding or removing initiators from a storage view
- Adding virtual volumes to a storage view
- Removing virtual volumes from a storage view
- Adding or removing metro node ports from a storage view
- Storage view status
- Storage group properties
- Director properties
- Cluster properties
- Moving data
- Mobility
- Move Data Within Cluster
- Move Data Across Clusters
- Create Mobility Job wizards
- Mobility job transfer size
- Creating a mobility job
- Viewing job details
- Committing a job
- Canceling a job
- Pausing a job
- Resuming a job
- Removing the record of a job
- Changing a job transfer size
- Searching for a job
- Mobility job status
- Notifications
NOTE: The chart displays data only for the directors in the cluster to which you are currently connected. To simultaneously
view front-end port latency for another cluster, open a second browser session and connect to the second cluster.
Guidelines
It is difficult to give absolute recommended values for front-end latencies since they are typically highly dependent upon
back-end latencies.
● Metro node processing overhead on read misses and on write operations (in a metro node Local system) is roughly 1msec.
● Be aware of large spikes in latency, which might correlate to front-end or back-end errors, or to a large front-end queue
depth.
Corrective actions
● Check CPU busy: If overly busy, the time for metro node to respond to I/O will increase.
● Check back-end latency: If on average the back-end latency is large, or there are large spikes, there could be a poorly
performing back-end fabric or an unhealthy, un-optimized, or over-loaded storage array. Perform a back-end fabric analysis,
and a performance analysis of all storage arrays in question.
● Check front-end aborts: The presence of these indicate that metro node is taking too long to respond to the host. These
might indicate problems with the front-end fabric, or slow SCSI reservations. See front-end aborts corrective actions.
● Check back-end errors: If the metro node back-end is required to retry an operation because it is aborted, then this will add
to the delay in completing the operation to the host. See back-end errors corrective actions.
● Check front-end queue depth: If this counter is large, this may explain larger than normal front-end latency. Follow front-end
operations count corrective actions.
● Check metro node write delta time: If the time spent within metro node is more than usual, attempt to find out why. See
corrective actions for write delta time.
The Front-end Latency chart allows you to:
● View front-end latency for a selected director or all directors
● Change the view to Read data only, Write data only, or both (default)
● Place the mouse over any point on the sent or received data indicators to view details for a specific director
Changing the view
Use the following appropriate selection criteria to filter the data:
● Read - Displays latency statistics pertaining to reads only.
● Write - Displays latency statistics pertaining to writes only.
● Director - Displays data for all directors or a specific director in the cluster.
Viewing the Front-end Latency chart
1. From the GUI main menu, click Performance.
2. In the Performance Dashboard, select the tab in which you want to display the Front-end Latency chart (or create a custom
tab).
3. Click +Add Content.
4. Click the Front-end Latency chart icon.
Front-end Throughput chart
The Front-End Throughput chart on the Performance Dashboard displays the front-end I/Os per second over time for
directors on your metro node system. Generally throughput (more commonly referred to as IOPS) is associated with small block
I/O (512B to 16KB I/O requests.)
NOTE:
The chart displays data only for the ports in the cluster to which you are currently connected. To simultaneously
view front-end throughput for another cluster, open a second browser session and connect to the second cluster.
Monitoring the system 41