[Nut-upsuser] I am a bit confused

Arjen de Korte nut+users at de-korte.org
Thu Jul 15 06:43:58 UTC 2010

Citeren Manuel Wolfshant <wolfy op nobugconsulting.ro>:

>> [...]In the past people have requested that the UPS should wait  
>> until the hard disks have been stopped (spun down), fearing that  
>> killing power to them abruptly might damage them. For that reason,  
>> we delay switching off the UPS. I'm not convinced that this is a  
>> real problem or just FUD, but adding the delay doesn't hurt either.
> hard disks no longer need this delay since '95 (sometime around the  
> era of 40 MB (!!) disks) or so when auto-parking the heads was  
> implemented.

I'm not sure when exactly this discussion took place, but it was well  
after '95. There supposedly is a marginal advantage in first sending  
the hard disk a command to power down, wait a few seconds and then  
cutting power to it (causing less wear on the mechanics). If memory  
serves, this whole discussion was rooted in the question if we should  
wait in the system halt script after 'upsdrvctl shutdown' for the UPS  
to kill the power (like suggested in the shutdown.txt document). As  
far as I can tell this discussion was in a Debian bug report, which  
asked for removal of this in the system halt script.

Best regards, Arjen
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