Summer 2013 and winter 2014, there were an inordinate number of power outages in Baker Lab, and other Chem buildings!

ChemIT's record of recent power outages

Date	Outage duration	Cause	Official link	ChemIT notes
4/11/16 Monday	About 40 minutes.	Unknown. Sun article, quoting Melissa Hines: http://cornellsun.com/2016/04/11/damaged-transmission-line-responsible-for-cornell-power-outage/		Servers mostly OK. Some UPS failings. Some router failings. See our notes on this particular outage.
2/27/2014 Thursday	2 minutes CU's record: Per 3/3/14 email: On Thursday 2/27/14 at 9:50am the campus experienced a disruption of electricity. The whole campus experienced an approximately 30 second outage. Many buildings on the central, west and north campus areas remained without power for 30 minutes to an hour. Oliver's record: Power outage at 9:53a. Restored at 9:55a (more than one minute).	Procedural error? Per 3/3/14 email: The outage was caused as a result of routine maintenance activities which were being conducted at the Campus’ main substation which takes power from the NYSEG transmission system and provides it to campus. This work has been conducted many times before without incident but in this case caused a major disruption of electricity supply. Staff from Utilities and external technical resources are investigating the root cause of this unexpected event.	No link to info in 3/3/14 email? Some delayed time-stamps, from the IT folks: http://www.it.cornell.edu/services/alert.cfm?id=3072 Initial timing info, from the power folks: http://www.cornell.edu/cuinfo/specialconditions/#2050	Michael led our effort to initially evaluate and restore systems, with Oliver adding to documentation and to-do's. Lulu completed the cluster restoration efforts. Lost 1-2 hours each for Michael, Lulu, and Oliver. Cornell called it a "power blip". In Oliver's books, any outage longer than seconds is not a "blip". Q: Broke one GPU workstation?
1/27/2014 Monday	17-19 minutes CU's record: Power outage at 2:22p. Restored around 2:41p. Oliver's record: Power outage at 2:22p. Restored at 2:39p.	?	http://www.it.cornell.edu/services/alert.cfm?id=3040	Lulu, Michael, and Oliver shut down head nodes and other systems which were on UPS. (Those systems non UPS shut down hard, per usual.) Lost 3 hours, for Lulu, Michael, and Oliver. Roger away on vacation (out of the U.S.)
12/23/2013 Monday	2 minutes CU's report: 08:36 AM - 8:38 AM (ChemIT staff not in yet.)	Procedural error?	http://www.it.cornell.edu/services/alert.cfm?id=2982	Terrible timing, right before the longest staff holiday of the year. ChemIT staff not present during failure. Lost most of the day, for Roger and Oliver. Michael Hint and Lulu way on vacation (out of the U.S.)
7/17/13	Half a morning (~2 hours) CU's report: 8:45 AM - 10:45 AM		http://www.it.cornell.edu/services/alert.cfm?id=2711

Question: When power is initially restored, do you trust it? Or might it simply kick back off in some circumstances?

Because we don't know the answer to this question following any specific power outage, we are reluctant to turn back on servers right away. Instead, we like to wait ~10-25 minutes.

Procedures and reminders

Reboot switches?

8 switches support the clusters (out of 12 in the room).

Start head nodes, if not on already

Only a few are on UPS. Those can obviously be left on.
None should be set to auto-start on power-off.

Confirm head nodes accessible via SSH

PuTTY on Windows

Use FMPro to get connection info?! (not the right info there, though...)

Menu => List Machine / User Selections = > List Group or selected criteria

Machine function => Server HN

Start compute nodes

If nodes done show up, consider:

Restart Torque scheduler on problematic nodes.
Try rebooting the switch the affected nodes are connected to, especially if the problematic nodes are grouped to a single switch.
Hook up a monitor as one of the high nodes boot.

See also