Dell EMC VxFlex Ready Node, User Manual

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When defining Fault Sets, we refer to the term fault units, where a fault unit can be
either a Fault Set, or an SDS not associated with a Fault Set (you may think of it as a
Fault Set of a single SDS).
There must be enough capacity within at least three fault units to enable mirroring.
If Fault Sets are defined, you can use any combination of fault units, for example:
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SDS1, SDS2, SDS3
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FS1, SDS1, SDS2
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FS1, FS2, SDS1
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FS1, FS2, FS3
Figure 3 Protection Domains, Storage Pools, and Fault Sets
To use Fault Sets, you must work in the following order:
1. Ensure that a Protection Domain exists, or add a new one.
2. Ensure that a Storage Pool and Fault Sets (minimum of three fault units) exist, or
add new ones.
3. Add the SDS, designating the Protection Domain and Fault Set, and at the same
time, adding the SDS devices into a Storage Pool.
The automated deployment and installation tools follow this order automatically.
You can only create and configure Fault Sets before adding SDSs to the system,
and configuring them incorrectly may prevent the creation of volumes. An SDS
can only be added to a Fault Set during the creation of the SDS.
You define Fault Sets and add SDSs to them during installation, using the following
management tools:
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Deployment wizard
You can also add Fault Sets when adding SDS nodes after initial installation.
Data layout
VxFlex OS offers a space efficient store layout with Fine Granularity (FG)
With FG, since space allocation occurs at 4KB, the data stored on the disk is
significantly reduced. Space allocation for Medium Granularity (MG) occurs at 1MB.
For FG, you must have NVDIMM configured as a DAX device. After NVDIMM is all set
up in your environment, you need to configure an NVDIMM Acceleration Pool (for
more information on Acceleration Pool, see "Acceleration Pools") and then you can
Architecture
32 Dell EMC VxFlex Ready Node AMS User Guide