[VMC] Understanding Automated Retrofit and Partition Placement Groups (PPG)

Products

• VMware Cloud on AWS

Issue/Introduction

To understand the automated retrofit process and partition placement groups (PPG) within VMware Cloud (VMC).

Cause

Partition Placement Groups were only available to new SDDC provisions when released. The Automated Retrofit process will enable this on any applicable existing deployments.

Resolution

Partition Placement Groups (PPG) places hosts in different logical partitions that do not share the same underlying hardware. This automatically deploys hosts across as many different partitions as there are available within an availability zone (AZ). Application availability is increased by using PPG and will also allow for isolation of host failures within a cluster. 

Partitions are not visible to users, and placement takes place automatically without any configuration from the user.  It is not recommended to share PPG status details with the end customer as they have no control over placement.
 

The Automated Retrofit process is an automated process that has been enabled to ensure proper PPG placement within existing SDDC deployments. The process functions identical to autoscaler activity as it will add a new host and then trigger a planned host removal. This activity will be logged in the SDDC activity log under "VMC Regular Maintenance". 

While this process is highly recommended, it can be disabled by working with the organization's VMware Account Representative. They will be able to submit a request to opt out of the Automatic Retrofit.

Additional Information

Impact/Risks:
The Automated Retrofit process is transparent and waits seven (7) days between back-to-back host replacements within a same cluster. This occurs with no more than one host per SDDC at a time.