Sun System Handbook - ISO 3.4 June 2011 Internal/Partner Edition | |||
|
|
Solution Type Problem Resolution Sure Solution 1003853.1 : Sun Fire[TM] 12/15/20/25K server found with DC Breaker in the 'off' position
PreviouslyPublishedAs 205408 Symptoms Either during onsite inspection, or through a customer call, it is noted that a DC (Direct Current) breaker on a Sun Fire[TM] 15K is unexpectedly in the 'off' position. Resolution BACKGROUND: Older Sun Fire[TM] 12K and 15K servers had exposed breakers that could be accidentally operated. It was not uncommon in the early days to find a server with a breaker that was powered off for no apparent reason. This was due to the ease with which a cable could drop down and flick off a breaker. This has bread an unhealthy trust in the belief that if a breaker is found in the 'off' position, that it can simply be flipped back on. The newer 15K's, 20 and 25K's have a shroud that protects the breakers from accidental operation, however, it's still possible to operate one of these switches without the knowledge that it has been switched off if the technician or customer are not completely focused on the task. The DC (Direct Current) breakers high end servers are designed to protect the platform from short circuits within the platform. They will turn off under one of a number of different conditions. Each of these possibilities MUST be considered when a DC breaker is found in the OFF positions. If the breaker has operated due to a short in the frame, simply turning the breaker back on could actually cause a COMPLETE platform outage. Don't do this, or we could end up with a REALLY unhappy customer. One more important fact to note is that the DC breakers are NOT instrumented. ie: The SC does not know directly if a DC breaker has flipped off. As a result of this, there are NO messages in the SC's logs relating to the breaker itself, although there WILL be messages relating to the SC's inability to communicate to the components that are located in the slot to which that DC breaker supplies power. In a platform where the entire system is not fully utilized, there is a good chance that this issue may go unnoticed for days, weeks, or even months. RESOLUTION: To remedy this situation, without unexpected interruption to the platform, the following action plan should be followed. - Request a PLATFORM OUTAGE. (ie: All domains down). - If the breaker remains ON, then it is most likely that there is no real problem and that the breaker was operated accidentally, or deliberately by the customer or field service representative. - If it flips OFF, we could well have a short within the frame, however, the possibility exists that this is being cause by a component within the system. - If after component replacement, the breaker again opens, we have a short within the frame, power chassis or power centreplane. Continue below at INTERNAL SHORT
INTERNAL SHORT
If an internal short is evident: Relief/Workaround As the high end servers are architected with a great deal of redundancy, the remainder of the platform will operate without issue with this fault present. As such, no workaround is required. Additional Information To familiarize yourself with the location of the DC-breakers, please take a look at the Sun Fire[TM] 15K - Service Views in the Sun[TM] Systems Handbookm available at: http://sunsolve2.central.sun.com/handbook_internal/Systems/SunFire15K/component.front_open.html. Product Sun Fire E25K Server Sun Fire E20K Server Sun Fire 15K Server Sun Fire 12K Server Internal Comments For examples of what lead to the creation of this doc, See PTS Escalations: 1-2680096 (Case 10567118 -- Internal Short) 1-8666013 (Case 64562580 -- No issue, likely accidental operation) 12k, 15k, 20k, 25k, Sun Fire, high end, breaker, DC, DC-DC, expander Previously Published As 81918 Product_uuid d842dd03-059b-11d8-84cb-080020a9ed93|Sun Fire E25K Server 1404a2d3-059a-11d8-84cb-080020a9ed93|Sun Fire E20K Server 29e4659c-0a18-11d6-9fa1-e67bbc033df8|Sun Fire 15K Server 077fd4c5-df8f-4320-ad69-7d01603a674d|Sun Fire 12K Server Attachments This solution has no attachment |
||||||||||||
|