RAID 5 Multiple Hard-drives failure

[Robin Laing]

Chris Wright wrote:
> Bob Chiodini wrote:
> 
>> On Tue, 2006-03-14 at 10:26 -0500, Reuben D. Budiardja wrote:
>>
>>> On Tuesday 14 March 2006 08:55, Bob Chiodini wrote:
>>>
>>>> On Tue, 2006-03-14 at 08:21 -0500, Reuben D. Budiardja wrote:
>>>
>>> <snip>
>>>
>>>> Reuben,
>>>>
>>>> Have you checked the power supply?
>>>
>>> I have not checked the power supply for the system. Any 
>>> recommendation on how to do so ?
>>>
>>>> Have all of your failures been in the same machine?
>>>
>>> Yes, all in the same machine, that's why I suspect there's something 
>>> else physically wrong.
>>>
>>> Thank you.
>>> RDB
>>> -- 
>>> Reuben D. Budiardja
>>> Dept. Physics and Astronomy
>>> University of Tennessee, Knoxville, TN
>>>
>>
>> Reuben,
>>
>> Open up the case and find an unused drive power connector.  Measure the
>> voltage between the yellow and black, should be ~12VDC.  The voltage
>> between the red and black should be ~5VDC.  I'm not sure what the
>> tolerances are for your drives, maybe it's on their website.  As a rule
>> of thumb, I'd not let the 12V get below 11.9V or above 12.1V (about
>> 10%). The 5V should be above 4.8V and below 5.1V.  These are guidelines.
>> The last time I opened a PC power supply the 12 and 5 volt supplies were
>> not independently adjustable.
>>
>> Your BIOS may also tell you these voltages, along with various
>> temperatures.  lm_sensors might work as well.
>>
>> Bob...  
> 
> 
> One thing to try when testing the power supply as above is to make sure 
> you 'load' the system.
> 
> When the system is idle (or close to idling), the 12V for example, might 
> be 11.99V.  But when you start spinning up multiple hard drives, this 
> puts a load on the power supply.
> If there is fault with the power supply, it will cause the voltages to 
> drop.
> 
> 'Most' PC PSU's are meant to be constant voltage type, ie. they try to 
> maintain their voltage outputs as close to spec as possible 
> (+5v,-5v,+12v,-12v, 3v etc etc etc).  If you took most PC PSU's out of 
> the case and measured their outputs with nothing connected, you would 
> read near exact values.
> 
> It is only when you place them under load that the outputs will vary or 
> indicate a fault.
> 
> So while measuring, try to run some sort of 'stress' test on select 
> items of kit / various items of kit.
> 
> Also worth pointing out, is that a lot of people these days are 
> inserting extra fans inside their machines, and these sometimes have 
> thermostatic controllers on them to switch them on at a certain temp.
> Some fans are electrically noisy, and of course, that noise will also 
> only be present when the fan is running.  Likewise, they will only 
> 'load' the system when they too are running.
> 
> So in summary, make sure you are running as much of a stress test as you 
> can (without making it a destructive stress test).
> 
> 
> Regards
> 
> Chris
> 

This may be a helpful link.

Do the Math to Get Your PC All the Power It Needs
<http://www.pcworld.com/howto/article/0,aid,119585,pg,2,00.asp>

I came across it when I was having problems burning DVD's.  Everything 
would go great until the very end or when ejecting the DVD.  I would 
have system freezes.  Changed the PS and all is well.

-- 
Robin Laing