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
Viewing the Back-end Bandwidth chart
1. From the GUI main menu, click Performance.
2. In the Performance Dashboard, select the tab in which you want to display the Back-end Bandwidth chart (or create a
custom tab).
3. Click +Add Content.
4. Click the Back-end Bandwidth icon.
Back-end Throughput chart
The Back-end Throughput chart shows the back-end I/Os per second over time for directors. Generally, throughput (or more
commonly referred to as IOPS) is associated with small block I/O (4KB or 16KB I/O requests.)
Each array type, model, and underlying hard disk drive is different. Ensure to know your array's capabilities, for example,
response time, IOPS, and bandwidth. Having a baseline of array performance is important so you know what your specific array
and its setup is capable of.
NOTE: The chart displays data only for the ports in the cluster to which you are currently connected. To simultaneously
view back-end throughput for another cluster, open a second browser session and connect to the second cluster.
Guidelines
● When adding metro node to an existing environment, know what your host to storage array (native) performance since
although metro node tends to boost read intensive workloads because of additional caching, often times metro node can only
perform just as well as this native performance.
● Metro node could simply be the victim of poor storage array performance.
● Unexpectedly low IOPS could indicate array saturation or back-end fabric issues. Recommended to check back-end aborts/
retries.
● Keep in mind many things affect storage-array IOPS performance such as:
○ IO request size
○ Read vs. write request
○ Underlying disk type (SSD, FC, SATA)
○ RAID type — 0, 1, 0+1, 5, 6
○ FAST VP — Fully Automated Storage Tiering across 3 distinct tiers: Flash, enterprise hard disk drives (10K and 15K rpm),
and high-capacity SATA HDDs
○ Thin/thick pools
○ Storage array cache settings and size
○ Running snapshots/clones
● For arrays with write-back caching, writes will generally be faster than reads. If the read data is cached by the array, then
the latency will be comparable to that of the writes.
● Performance can be negatively affected while running snapshots or clones.
● For Symmetrix arrays, performance can be impacted by Write Pending (WP) limits when there is a lack of available free
cache slots to accept incoming writes, forcing the array to proactively flush pages to disk. Running SRDF sessions might also
affect performance.
● For CLARiiON arrays, performance can be impacted by forced flushes due to the lack of available cache to buffer writes.
Corrective actions
● Check back-end errors: These indicate that metro node had to abort and re-try operations. Could be a back-end fabric or
storage-array health issue.
● Examine the back-end fabric for its overall health state, recent changes, reported errors, and properly negotiated speeds.
● Examine the back-end storage array for general health state, and that performance best practices are followed for disk/
RAID layout when needed.
● Utilize available performance monitoring tools from the storage array vendor to confirm the array's performance. Additional
metrics available to the array but not visible to metro node might shed light on the problem.
● Ensure to run the recommended storage array firmware version. Check for newer software releases and known bug fixes.
● Consult your storage array vendor's performance specialists if the problem persists.
Monitoring the system
33