Today labservices1001 went down and toolschecker complained about all tests failing.
The failure itself seems hardware related, host down was at 2:17
```
$ sudo grep mcelog syslog
Dec 4 01:56:22 labservices1001 mcelog: mcelog read: Function not implemented
Dec 4 01:56:22 labservices1001 mcelog: Processor 1 heated above trip temperature. Throttling enabled.
Dec 4 01:56:22 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 01:56:22 labservices1001 mcelog: Processor 1 below trip temperature. Throttling disabled
Dec 4 01:58:52 labservices1001 mcelog: Processor 3 heated above trip temperature. Throttling enabled.
Dec 4 01:58:52 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 01:58:52 labservices1001 mcelog: Processor 3 below trip temperature. Throttling disabled
Dec 4 02:06:22 labservices1001 mcelog: Processor 3 heated above trip temperature. Throttling enabled.
Dec 4 02:06:22 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 02:06:22 labservices1001 mcelog: Processor 3 below trip temperature. Throttling disabled
Dec 4 02:08:52 labservices1001 mcelog: Processor 3 heated above trip temperature. Throttling enabled.
Dec 4 02:08:52 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 02:08:52 labservices1001 mcelog: Processor 3 below trip temperature. Throttling disabled
Dec 4 02:12:37 labservices1001 mcelog: Processor 1 heated above trip temperature. Throttling enabled.
Dec 4 02:12:37 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 02:12:37 labservices1001 mcelog: Processor 2 heated above trip temperature. Throttling enabled.
Dec 4 02:12:37 labservices1001 mcelog: Please check your system cooling. Performance will be impacted
Dec 4 02:42:00 labservices1001 mcelog: failed to prefill DIMM database from DMI data
```
And before that labservices1001 saw high disk I/O starting at around 1.00 UTC which might have been a trigger
https://grafana.wikimedia.org/dashboard/db/prometheus-machine-stats?var-server=labservices1001%3A9100&var-datasource=eqiad%20prometheus%2Fops&from=1480812690403&to=1480818733445
Note that during this time dns from labs instances seemed fine, why toolschecker failed needs investigation