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
● Check for bandwidth/IOPS over-provisioned metro node front-end ports. Be sure to balance hosts and LUNs across
the available directors and front-end ports presented from metro node. Check the front-end fabric for saturation or over-
capacity.
● Verify that front-end FC ports, HBAs and switch ports are configured to the correct port speeds.
● Configure your host multipathing software based on metro node best practices, and ensure the installed software versions
are compatible with metro node. For more information on compatibility, see the Dell EMC Simple Support Matrix for metro
node document, available on Dell EMC Online Support and on the SolVe Online.
For metro node Metro configurations
● Check the health of the inter-cluster link and maximum performance capabilities. From the GUI, check the inter-cluster
WAN bandwidth. If your application throughput appears low and seems to only achieve something similar to what the WAN
bandwidth reports, then you are probably limited by the WAN. Therefore:
○ Make sure you have provisioned enough inter-cluster bandwidth for the desired application workload. Verify that
your WAN configuration is supported by metro node (minimum supported bandwidth, supported inter-cluster latency,
compatible WAN hardware and software).
○ For Metro-FC, if the inter-cluster WAN is over a FC fabric, confirm that you have allocated enough buffer credits or that
you have configured the FC WAN ports correctly on your switches. Check for buffer credit starvation, c3 discards, and
CRC errors. Some vendors may require extended fabric licenses to enable WAN features.
○ Validate your WAN performance before going live in production. Create multiple test distributed devices and force them
to rebuild. Observe the performance of the rebuilds.
● When troubleshooting distributed device performance, if feasible, check local device performance. Export a test LUN from
your storage array to metro node, then to the host, and then run a test I/O workload.
● Check for any unexpected local or distributed rebuilds or data migrations. There will be some amount of performance impact
to host application traffic that relies on the same virtual volumes and storage volumes. Tune the rebuild transfer-size setting
to limit the performance impact of rebuild and migrations. Consider scheduling migrations during off-peak hours.
Changing the view
To view the throughput of a single director in your metro node system, select the director name from the Director drop-down.
Viewing the Virtual Volumes Throughput chart
1. From the GUI main menu, click Performance.
2. Click + and select Add Virtual Volumes Dashboard.
Virtual Volume Latency chart
The Virtual Volume Latency chart provides a time-based view of the IO Latency for a virtual volume broken down by read
and write latency. Virtual volume latency is defined as the amount of time an I/O spends within metro node for a given virtual
volume. The reported metro node front-end latency should match closely to the host or application reported volume latency
unless there is significant added delay in the front-end fabric, HBA, multi-pathing software or host operating system software.
For metro node cache read miss operations, it includes the time spent retrieving the disk blocks from the storage array.
Therefore, for non-metro node cached operations, front-end latency can perform only as fast as the back-end array. Contrast
cache read misses to cache hit operations which will be fast. Read miss and hit latency is not reported separately in the
read-latency metric, so it will be difficult to know the performance of each.
It is important to distinguish how front-end latency write operations behave in the following metro node configurations:
● For metro node Local write operations, it includes the time spent protecting the disk blocks to one or more local storage
arrays.
● For metro node Metro write operations to distributed-devices, it includes the time spent protecting the disk blocks to the
storage array at both clusters. When writing to the remote cluster, the round-trip time on the WAN links will add to the
front-end latency, depending upon the network delay observed between clusters.
Guidelines
Keep the following guidelines in mind when using this chart:
Monitoring the system
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