Administrator Guide
Table Of Contents
- Dell EMC Storage Systems Administrator Guide for PowerStore and Unity XT metro node feature
- CLI Workspace and User Accounts
- Meta Volumes
- System Management
- Thin support in metro node
- Provisioning Storage
- Volume expansion
- Data migration
- About data migrations
- Migrating thin-capable storage
- About rebuilds
- One-time data migrations
- Batch migrations
- Prerequisites
- Creating a batch migration plan
- Checking a batch migration plan
- Modifying a batch migration file
- Starting a batch migration
- Pausing/resuming a batch migration (optional)
- Canceling a batch migration (optional)
- Monitoring a batch migration’s progress
- Viewing a batch migration’s status
- Committing a batch migration
- Cleaning a batch migration
- Removing batch migration records
- Configure the WAN Network
- Consistency Groups
- Performance and Monitoring
- Metro node with active-passive storage arrays
- Index
Enable/disable CAW as system default
Use the set command in /clusters/cluster context to enable or disable CAW for the entire cluster.
To enable CAW as the cluster system default:
VPlexcli:/clusters/cluster-1> set default-caw-template true
To disable CAW as the cluster system default:
VPlexcli:/clusters/cluster-1> set default-caw-template false
CAW statistics
CAW performance statistics are included for front-end volume (fe-lu), front-end port (fe-prt), and front-end director (fe-
director) targets.
See Statistics tables on page 97 for a listing of the available statistics. Statistics for fe-director targets are collected as a part
of the automatically created perpetual monitor.
You can create a monitor to collect CAW statistics, which can be especially useful for fe-lu targets (because there can be very
large numbers of volumes involved, these statistics are not always collected).
WriteSame (16)
The WriteSame (16) SCSI command provides a mechanism to offload initializing virtual disks to metro node. WriteSame (16)
requests the server to write blocks of data transferred by the application client to consecutive logical blocks multiple times.
WriteSame (16) is used to offload virtual machine provisioning and snapshotting in vSphere to metro node.
WriteSame (16) enables the array to perform copy operations independently without using host cycles. The array can schedule
and execute the copy function much more efficiently.
Metro node support for WriteSame (16) is enabled by default.
Enabling/disabling WriteSame (16)
CAUTION:
WriteSame (16) can be enabled/disabled on metro node only by Dell EMC Technical Support
personnel.
VMware servers discover whether the WriteSame (16) SCSI command is supported:
● During initial storage scanning
● When the DataMover.HardwareAcceleratedInit value on the ESX host is enabled (or toggled if it is enabled)
NOTE:
To toggle the value — In the vSphere client, toggle host > Configuration > Software > Advanced Settings >
DataMover.HardwareAcceleratedInit value to 0 and then 1.
Virtual Machine operations may experience significant performance degradation if WriteSame (16) is not enabled.
Metro node allows WriteSame (16) to be enabled/disabled for all storage associated with metro node, using a single command.
When WriteSame (16) is disabled on metro node, storage volumes, do not include WriteSame (16) support information in their
responses to inquiries from hosts.
Support for WriteSame (16) can be enabled or disabled at two levels:
● Storage view - Enabled or disabled for all existing storage views. A storage view created after WriteSame (16) is enabled/
disabled at the storage view level inherits the system default setting. Dell EMC recommends maintaining uniform WriteSame
(16) setting on all storage views in metro node.
If WriteSame (16) must be disabled for a given storage view, it must be disabled on all existing and future storage views. To
make future storage views to reflect the new setting, change the system default.
● System default - Enabled or disabled as a system default. A storage view created after WriteSame (16) is enabled/disabled
at the system default level inherits the system default setting. If the system default is enabled, WriteSame (16) support for
the new storage view is also enabled.
System Management
19