Dell EMC OpenManage Integration Version 2.0 with Microsoft Windows Admin Center User’s Guide

Azure stack HCI cluster works best when the hardware configurations of all the selected nodes are compliant with Dell EMC recommendations.

The Integrated Deploy and Update feature in OMIMSWAC helps you to maintain hardware symmetry and update nodes while creating an Azure Stack HCI cluster using AX nodes (running Azure Stack HCI OS) in Windows Admin Center. The Hardware symmetry check runs a set of rules on nodes and helps you to align their hardware configurations with Dell EMC recommendations.

Before you create an Azure Stack HCI cluster, ensure to run and comply with all the rules of Hardware symmetry checks.

Hardware symmetry checks are intended to do the following:

• Find hardware or configuration issues before an Azure stack HCI cluster goes into production.
• Ensure that the Azure stack HCI cluster you deploy is reliable and the cluster performance is optimal.

This topic explains the Hardware symmetry rules and provides examples of supported and unsupported configurations. For information about supported and validated components required for hardware symmetry, see AS HCI support matrix. If any of the hardware symmetry checks fail with a "Critical" or "Warning" error, review the recommendations and show details and contact the Dell support team to resolve the issue before proceeding to the next step.

The critical error states that this aspect of nodes configuration is not supported. You must correct the issue before you can deploy an symmetric Azure Stack HCI cluster. And Warning states that this aspect of nodes configuration can be supported for cluster deployment, but might result in sub-optimal cluster performance. Therefore, it should be reviewed.

Symmetry rules

• If one node has persistent memory, it is recommended they should all have the persistent memory of same number and capacity. Using nodes with different numbers or capacities of persistent memory results in a warning.
• It is recommended to have the same amount of physical memory for all nodes. Using physical memory of different capacity results in a warning.

• It is recommended to have compatible drives of same media type such as SSD, NVMe, and HDD for all nodes. Using nodes with incompatible drives results in a warning.
• All nodes must have the same Host Bus Adapter (HBA) except for all NVMe configurations. Using nodes with different HBA results in Hardware symmetry failure.

  For example, if one node has HBA 330, they should all have the same HBA 330.

Disks

• It is recommended that all nodes should contain compatible disks as mentioned in the AS HCI support matrix. Using nodes with incompatible disks results in a warning.
• It is recommended that all nodes should contain up to two media types. Supported media type combinations are as follows:
  • Persistent Memory and NVMe
  • Persistent Memory and SSD
  • NVMe and SSD
  • NVMe and HDD
  • SSD and HDD
  • ALL NVMe
  • ALL SSD

  Using combination of three media types such as NVMe, SSD and HDD results in Hardware symmetry failure.

• It is recommended that all nodes should have minimum number of drives required per media type.

  For example, if a node has only 1 media type of SSD, then at least 4 capacity drives of SSD are required.

  If a node has 2 media types such as SSD and HDD, then 2 SSD drives for cache and 4 HDD drives for capacity are required.

  Using media types with different drives results in a warning.

• It is recommended that all drives of each media type such as SSD, NVMe, and HDD have the same bus protocol such as SAS, SATA, or PCIe.
  For example, if one node has SSD and HDD drives with SAS bus protocol, other nodes should also have SSD and HDD drives with SAS bus protocol. Using drives of different bus protocols results in a warning.

  NOTE It is recommended that drives across selected nodes have the same bus protocol to achieve symmetrical configuration. For example, nodes with drives such as SSD and HDD with SATA and SAS bus protocols respectively are not a supported configuration.
• It is recommended that all nodes should have drives of equal size and count per media type.

  For example, If one node has 4 SSD drives of 2 TB size, other nodes should also have 4 SSD drives of 2 TB size. Using nodes with different count and capacity results in a warning.

• It is recommended for each node having drives of SSD or NVMe media type to have the same endurance.

  For example, If one node has 4 Mixed Use SSD drive type, other nodes should also have 4 Mixed Use SSD drive type.

  Using nodes with drives of different endurance such as Read intensive, Mixed Use, and Write Intensive results in a warning.

• If persistent memory is present on at least one node, all the remaining nodes selected for the cluster should also contain the same number and capacity of persistent memory modules. Using nodes with different persistent memory modules results in a warning.

Example configurations

Here are some supported and unsupported configurations:

Not supported: different models between nodes

Supported: no more than two media types

Supported configuration for two media types are as follows:

Not supported: at least minimum number of drives

If two media types exist:

This is not supported. Nodes with two media types drives should have 2 SSD drives for cache and 4 HDD drives for capacity.

Supported: at least minimum number of drives

If two media types exist, supported configurations are:

This is supported. Nodes with two media types drives should have 2 cache drives (SSD/NVMe/AEP) and 4 capacity drives (HDD/SSD/NVMe).

Not supported: drives with different bus protocol

The first two nodes use SSD drive with SAS bus protocol but the third node uses SSD drive with SATA bus protocol.

The first two nodes use SSD and HDD drives with SAS bus protocol but the third node uses HDD drive with SATA bus protocol.

These are not supported. Drives across nodes should have the same bus protocol for symmetrical configuration.

Not supported: drives with same capacity and different count

The first two nodes use 2TB SSD and the last node uses 3TB SSD. Every node has total 4 SSD.

This is not supported. All drives of each media type (SSD/NVMe/HDD) should be of the same count and capacity.

Not supported: at least one same RDMA network adapter present in all nodes

The first two nodes use Qlogic network adapter and the last node uses Mellanox network adapter.

This is not supported. One network adapters should be common across all nodes.

View Hardware symmetry check results

After the Hardware symmetry check has completed, the summary report is displayed. All rules must pass with a green check mark, or in some cases, a yellow triangle (warning). The following table shows the symbols in the summary and explains what they mean:

Symbols	Description
	The Hardware symmetry check passed, indicating that this aspect of nodes configuration is supported for the cluster deployment.
	The Hardware symmetry check produced a warning, indicating that this aspect of nodes configuration can be supported for cluster deployment, but might result in sub-optimal cluster performance. Therefore, it should be reviewed.
	The Hardware symmetry check failed, and this aspect of nodes configuration is not supported. You must correct the issue before you can deploy an symmetric Azure Stack HCI cluster.