Further notekeeping:
- 4 dd's (xenial+nohz=off) has survived for half a day, then the instance crashed on something else.
- trusty and vivid kernels with nohz=off have survived for a full day without any lockups. lxd on trusty kernel causes a lot of leaked "FREEZED/FREEZING" containers, but that's unrelated and does not happen with the vivid kernel. So it's unclear whether this combination is stable or the lockups are just reduced, or it just was lucky.
- trusty kernel without the nohz option locked up a few minutes after reboot, without actually running any test.
Further notekeeping:
- 4 dd's (xenial+nohz=off) has survived for half a day, then the instance crashed on something else.
- trusty and vivid kernels with nohz=off have survived for a full day without any lockups. lxd on trusty kernel causes a lot of leaked "FREEZED/FREEZING" containers, but that's unrelated and does not happen with the vivid kernel. So it's unclear whether this combination is stable or the lockups are just reduced, or it just was lucky.
- trusty kernel without the nohz option locked up a few minutes after reboot, without actually running any test.