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
Changing the view
To view the Front-end Queue Depth of a single director in your metro node system, select the director name from the Director
drop-down.
NOTE: The chart displays data only for the directors in the cluster to which you are currently connected. To simultaneously
view Front-end Queue Depth for another cluster, open a second browser session and connect to the second cluster.
Viewing the Front-end Queue Depth 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 Queue Depth chart (or create a
custom tab).
3. Click +Add Content.
4. Click the Front-end Queue Depth chart icon.
Front-end Bandwidth chart
The Front-End Bandwidth chart on the Performance Dashboard displays the quantity of front-end reads and writes per
second over time for directors on your metro node system. Generally bandwidth (measured in KB/s or MB/s) is associated with
large block I/O (64KB or greater I/O requests).
NOTE: The chart displays data only for the cluster to which you are currently connected. To simultaneously view front end
bandwidth charts for another cluster, open a second browser session and connect to the second cluster.
Guidelines
● Front-end performance should be compared to baseline numbers (native host to storage-array) when metro node
performance issues arise. The underlying problem could be poor storage array performance. When you add metro node
to your environment, know what your application throughput was beforehand.
● Front-end performance in metro node depends heavily upon the available back-end storage-array performance, and in Metro
configurations, the WAN performance for distributed devices.
● Any running distributed rebuilds or data migrations might negatively affect available host throughput.
● Since metro node Local and Metro implement write through caching, naturally a small amount of write latency overhead
(typically <1msec) is expected with metro node. This latency may affect applications that serialize their I/O and don't take
advantage of multiple outstanding operations. These types of applications may see a throughput and IOPS drop with metro
node in the data path.
● Understand that in a metro node Metro environment you incur extra WAN round-trip time on your write latency since writes
need to be successfully written to each cluster's storage before the host is acknowledged. This extra latency could impact
the throughput and IOPS of serialized-type applications.
Corrective actions
● Check CPU busy: If overly busy, metro node will be limited on the amount of bandwidth it can provide.
● 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.
● 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.
● 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.
Monitoring the system
39