[rubiquity]

Disclaimer: I work at AWS, not on EC2.

Locally attached disks are not ephemeral to instance reboots/power failures. However, the disks are wiped after instance terminations. On the official EC2 product pages this is called "instance storage" not "ephemeral storage."

[tommyzli]

TIL, this is really good to know! Do you know offhand if this is a new feature, or have I just always been wrong

[sk5t]

It's been that way for a long time - years at least. You can reboot but not 'stop' and of course not 'terminate.'