Migrating from Vultr to AWS

Both approaches you've outlined are valid, but I would recommend a modified version of Approach 1 as it offers more control and reliability for your specific scenario. Here's a refined approach:

1. Set up your AWS environment:

   • Create a VPC with appropriate subnets
   • Set up security groups (AWS's firewall equivalent) with the required rules (SSH, HTTP, HTTPS)
   • Create three EC2 instances that match or exceed your current Vultr specifications

2. For Server 1 (8 GB RAM, 4 vCPU), consider using an i7ie.large instance. It provides 2 vCPUs and 16 GB of RAM, which exceeds your current specs. For storage, you can attach an EBS volume for the required 150 GB.

3. For Server 2 (4 GB RAM, 2 vCPU), an i7ie.large instance would also work well, providing more resources than your current setup.

4. For Server 3 (0.5 GB RAM, 1 vCPU), a t3.nano or t3.micro instance would be suitable, depending on your specific needs.

5. Ensure all instances are in the same VPC and can communicate with each other.

6. Use AWS Application Migration Service (MGN) to replicate your Vultr instances to AWS. While you mentioned uncertainty about its reliability, MGN is actually a robust tool designed for this purpose and can significantly simplify the migration process.

7. Once the replication is complete, perform a test cutover to ensure everything is working correctly in the AWS environment.

8. Configure the new VPC IP addresses in your application environments.

9. Update your DNS records to point to the new AWS instances.

10. Perform the final cutover and verify all systems are functioning correctly.

11. Once confirmed, you can decommission your Vultr instances.

This approach combines the control of manual migration with the efficiency of AWS's migration tools. It also ensures you're using appropriate AWS services from the start.

Regarding your question about upgrading or replicating the machines later: Yes, AWS provides great flexibility for this. You can easily change the instance type to upgrade resources, and you can create Amazon Machine Images (AMIs) of your instances for replication or backup purposes. Additionally, you could consider using Auto Scaling groups for automatic replication and load balancing if your application architecture supports it.

Remember to thoroughly test your applications in the new environment before the final cutover. Also, consider using AWS's monitoring and management tools like CloudWatch and Systems Manager to help manage your new infrastructure effectively.
Sources
Amazon EC2 I7ie instances - Amazon Web Services
Guidance for Migrating VMware Virtual Machines to Amazon EC2
Accelerate VMware Migration to AWS with AWS Application Migration Service and the Agentless vCenter Client | AWS re:Post

I tried running the AWS Replication Agent and this is what I got:

The installation of the AWS Replication Agent has started.
Identifying volumes for replication.
Identified volume for replication: /dev/vda of size 50 GiB
All volumes for replication were successfully identified.
Downloading the AWS Replication Agent onto the source server... 
Finished.
Installing the AWS Replication Agent onto the source server... 

Error: Your Linux kernel version is not supported.
Installation failed.
Learn more about installation issues in our documentation at https://docs.aws.amazon.com/mgn/latest/ug/Troubleshooting-Agent-Issues.html#Error-Installation-Failed
linuxuser@vultr:~$ uname -r
6.11.0-21-generic
linuxuser@vultr:~$ ls -l /usr/src
total 20
drwxr-xr-x 26 root root 4096 Mar 17 19:38 linux-headers-6.11.0-19
drwxr-xr-x  7 root root 4096 Mar 17 19:38 linux-headers-6.11.0-19-generic
drwxr-xr-x 26 root root 4096 Mar 24 22:48 linux-headers-6.11.0-21
drwxr-xr-x  7 root root 4096 Mar 24 22:48 linux-headers-6.11.0-21-generic
drwxr-xr-x  4 root root 4096 Mar 17 19:41 python3.12
linuxuser@vultr:~$ sudo apt-get install linux-headers-`uname -r`
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
linux-headers-6.11.0-21-generic is already the newest version (6.11.0-21.21).
The following packages were automatically installed and are no longer required:
  bridge-utils dns-root-data dnsmasq-base ubuntu-fan
Use 'sudo apt autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 5 not upgraded.
linuxuser@vultr:~$ which make
/usr/bin/make

I then tried to rerun the replication agent installation but got the same error.