Erasure Coding enables significant space reduction. An erasure coding 3+1, also known as Network RAID-5 3+1, can give us 50% more usable capacity than a RAID-1 Mirroring policy. Erasure Coding 3+1 requires a minimum of 4 Fault Domains/Hosts.
In this environment, there are four nodes in this VxRail Cluster.
In this post, we will learn how to create the storage policy in Dell EMC VxRail 4.0 and assign the storage policy into the virutal machines. First login into vCenter server in vSphere Web Client. You will now execute a set of steps to create a new storage policy.
Click Policies and Profiles.
Create the new storage policy.
Input the Name of storage policy, then Next.
Click <Add rule> Select Failure Tolerance method based on the below settings. Then Next.
Once the storage policy is created, you can assign this storage policy “Erasure Coding” into the virtual machines.
Rigth click of the virutal machine, select VM Policies and Edit VM Storage Policies.
In the VM storage policy list box, select the policy you created, Erasure Coding.
Click Apply to all. Click OK.
NOTE: After applying a new policy to a VM, it is important to verify that the VM complies to the new rules. Incertain policy changes, such as changes in QoS limits, the VMs will become compliant almost immediately but when changing rules like fault tolerance mode, it will take some time for the VM to become compliant because the adaptation to the new rules require data movement. In the following steps you will check the VM compliance and monitor the component reconfiguration process.
Finally you should go to monitor component reconfiguration,
Click on the Monitor tab. Click on the Policies tab
Select Hard disk1
Click Physical Disk Placement.
Check the Component State column. It may display “reconfiguring” or “active”.
Observe that there are 4 components associated to the “Hard Disk 1 – RAID-5 object”.
Each component is in a different Fault Domain.
NOTE: Erasure Coding requires to enable Fault Domains in VSAN Cluster.