On at least two occasions I was forced to recreate an instance on AWS. They send out an email similar to this:

> We have important news about your account (AWS Account ID: 288053528466). EC2 has detected degradation of the underlying hardware hosting your Amazon EC2 instance (instance-ID: i-0480b1eb4617c84f3) in the us-east-1 region. Due to this degradation, your instance could already be unreachable. After 2016-08-16 01:00 UTC your instance, which has an EBS volume as the root device, will be stopped.

I’ve had that happen a couple of times but it’s definitely uncommon (single digit count for hundreds of instances over a decade). I haven’t seen it in a long enough time that I’m assuming they have a bulletproof live migration feature now.

Could live-migration prevent that happening today? Depends on the nature of the degradation I imagine.

That's where VMware on aws comes in ;) you get vmotion, so no downtime due to planned maintenance

I was thinking of live migration performed by AWS. Are there situations where running your own VMware could help, beyond what AWS can do themselves? If there's a sudden outage, neither helps, as the instance disappears. If there's a minor issue, either should be possible.

Well, if your instance is important enough, there's vSphere Fault Tolerance [0]:

> You can use vSphere Fault Tolerance (FT) for most mission critical virtual machines. FT provides continuous availability for such a virtual machine by creating and maintaining another VM that is identical and continuously available to replace it in the event of a failover situation.

> The protected virtual machine is called the Primary VM. The duplicate virtual machine, the Secondary VM, is created and runs on another host. The primary VM is continuously replicated to the secondary VM so that the secondary VM can take over at any point, thereby providing Fault Tolerant protection.

> ...

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[0]: https://docs.vmware.com/en/VMware-vSphere/6.7/com.vmware.vsp...

GCP wins on the longest uptimes because of their superior Live Migration feature. I've never had a host failure or update issue yet in 5 years.

I had a kernel panic once on GCP that I attribute to a live migration. Panic was something along the lines of

    sched: Unexpected reschedule of offline CPU#1!

My DigitalOcean droplet is over 750 days now. I'm very happy and proud of what they offer for budget conscious users.

I was under the impression that AWS needs to do mandatory guest power cycles in order to update underlying infrastructure (e.g. to mitigate Meltdown, Spectre, L1TF, MDS, etc.). Is that not the case? Has the instance actually been up since 2016?

I had a Windows Server 2008R2 instance running SQL 2008 for over 10 years from 2008-2018 that I only rebooted myself a handful of times. It had ephemeral disks because that's all there was when it was launched so the hardware never changed. There was an unexpected reboot once in 10 years. In 2008 people told me I was crazy to run SQL let alone Windows in AWS. I never had a complaint.

I eventually switched to RDS to save some money.

I have another 2008R2 server running IIS that was launched at the same time and is still in service on the same hardware.

I don't have inside knowledge on AWS but I do know OpenStack (open source cloud infrastructure project) and it's had the ability to live migrate guest VMs for years so I'd be shocked if AWS can't move VMs and cycle hosts to swap failing hardware or apply firmware / ring 0 hypervisor updates.

This is an infamous gap, and AWS has had to reboot customer instances in the past: https://www.quora.com/Why-cant-Amazon-AWS-migrate-a-live-ins...

The question is whether something has changed.