Maintenance; Maintaining The Physical Layer; Instant Maintenance Mode - Dell EMC VxFlex Ready Node User Manual

Maintenance

Maintaining the physical layer

Instant maintenance mode

SDS device management
Devices are managed in the following way:
Direct I/O
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Device management is performed on the host directly, yielding the best I/O
performance. Devices are added to the system after the deployment. On factory-
installed VxFlex Ready Node servers, the AMS configures the optimal device
configuration on the Linux servers and adds devices to the system.
Deployment considerations
Take the following into account:
Pre-deployment
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Are there flash devices that will be added to the SDS?
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Do you want to create Fault Sets? See the requirements in the "Fault sets"
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section.
Post-deployment
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AMS sets all VxFlex OS processes to start automatically with boot of the
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nodes. Do not set change the settings unless instructed by VxFlex OS
guidelines.
Manually install SDC on the application nodes.
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Maintenance of VxFlex OS is primarily limited to configuration changes of the physical
and virtual layers. It requires minimal user attention. When maintenance or planned
restart of an SDS is required, the maintenance mode feature can be used to streamline
system operation.
In the physical layer, maintenance is limited to adding and removing hardware units
and configuring them into VxFlex OS. These operations are usually a result of:
Scaling out when there is a need for additional capacity. This usually results in
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adding more storage media to the existing servers, or adding additional servers.
Hardware failure. In cases where there is a hardware (storage media or server)
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failure and it needs to be replaced.
In all of the above cases, the operation will require adding or removing storage
capacity from the system. In some cases, it may include adding or removing an
entire server, and its associated storage media, from the configuration. As far as
VxFlex OS is concerned, all of these activities translate to SDS reconfigurations.
If the removed server is an SDC node, or the server to be added requires exposing
storage locally, SDC reconfiguration will happen as well.
Adding or removing storage media. Add or remove the media from the SDS with
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which it is associated. VxFlex OS will redistribute the data accordingly and
seamlessly.
Instant maintenance mode enables you to restart a server that hosts an SDS, with
minimal impact on VxFlex OS, thus bypassing the disruption and effort caused by
disorderly shutdown, Protection Domain shutdown, and orderly shutdown.
Dell EMC VxFlex Ready Node AMS User Guide
Architecture
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