AWS MacOS Dedicated Host Characteristics

Critical Differences from Linux VMs

⚠️ IMPORTANT: MacOS dedicated hosts are fundamentally different from typical Linux VMs:

• Bare Metal Hardware: Although VMs are created for jobs in the MacOS hosts, the hosts are physical Mac machines (Dedicated Hosts on AWS) not virtualized instances.
• Provisioning Time: Can take hours to provision a new dedicated host.
• Deprovisioning Time: Can take hours to fully release and clean up.
• Limited Availability: Hardware availability is constrained by AWS’s allocation by region and zones.

How AWS Dedicated Hosts Boot

1. Runs a “control” MacOS managed by AWS
2. Creates a second bootable OS from your AMI
3. Reboots the machine to use the custom OS

Dedicated Host Limitations

• Provisioning Speed: Unlike Linux VMs, provisioning a host is slow as it involves creating a second OS from an AMI (EBS volume).
• Availability Issues: Frequent problems acquiring instances in specific zones, often requiring hours of waiting across multiple availability zones.
• Release Delays: Releasing a dedicated host can take hours as the control OS must wipe the SSD before reuse.
• Regional Constraints: MacOS machine types are limited to specific AWS regions.
• Apple Licensing: Minimum 24-hour hold time per Apple OS licensing requirements - hosts cannot be released before this period.
• Cost: Approximately $1,000 per month per host.