Dell EMC VxFlex Ready Node - Maintaining the Virtualization Layer; Management Tools

Whereas VxFlex OS always uses two copies of user data, invoking maintenance mode
introduces an additional copy that stores all writes created during maintenance to an
SDS or Fault Set (created during maintenance) in both a primary location and a new
location. This copy prevents data loss if a single failure occurs.
When the SDS or Fault Set is returned from maintenance mode, only the new writes
are required to be resynchronized, thus minimizing data transfer during and after the
update.
Instant maintenance mode does not interrupt application IOs; it can be run on any
amount of members of a Fault Set; and it can run in parallel on different Protection
Domains. While an SDS is in maintenance mode, most VxFlex OS operations (like
adding a volume) cannot be performed in the Fault Set, Protection Domain, or Storage
Pool in which the SDS and its devices reside.
To invoke maintenance mode, the following conditions are required:
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Only one Fault Unit (or standalone SDS) can be in maintenance mode at any given
time.
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No other SDSs can be in degraded or failed state (force override can be used).
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There must be adequate space on other SDSs for the additional backup (force
override can be used).
Note: Use of force override options when entering maintenance mode can lead
to data unavailability while maintenance mode is activated.
While an SDS is in maintenance mode, it can be shut down with no danger to data.
Adding or removing a server
When adding or removing servers, VxFlex OS redistributes the data accordingly and
seamlessly.
Maintaining the virtualization layer
The following operations may be performed on volumes that are exposed by the
VxFlex OS virtual SAN:
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Add or remove a volume:
Create or delete a volume in the system.
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Increase volume size:
Add capacity to a given volume, as needed. The change in volume size occurs
seamlessly without interrupting I/O.
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Map and unmap volumes to an SDC:
This enables or disables access to a volume by an SDC, and thus by an application
residing on the same node.
Management tools
This section lists the available management clients that can be used with VxFlex OS.
Many of VxFlex OS actions can be performed using more than one tool.
You can provision, maintain, and monitor VxFlex OS using the following management
clients:
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Command Line Interface (CLI)
The CLI enables you to perform the entire set of configure, maintain, and monitor
activities in VxFlex OS.
Architecture
74 Dell EMC VxFlex Ready Node AMS User Guide