[fred256]

Not sure. Perhaps it might be a reference to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518457 which caused 100% CPU usage (and thus throttling) on t2 instances in some cases.

[mattbillenstein]

Disabling hotadd also fixes I/O errors on nvme disks on the new i3 instances which is mentioned here as well.