Hard drive behavior on power cut

[THS]

What happens in the ide controller under a power cut?
I have some problems with a corrupt compact flash card after a power cut even when cutting the power without writing to the disk (diskperf shows no activity). I have heard some rumours telling that NT4 (I'm running NT 4 Embedded) is trying to do some desperate disk writing (flushing?) when a power cut is detected and its life is fading away. The rumours also told that there should be some registry settings that prevented this behavior. I have not been able to find this settings. Does anyone know anything about this?

Regards,
Thomas Solvik

 

[satrow]

Firstly, check in the Bios that your machine is set not to restart after a power failure; more damage can occur then as the power tends to fluctuate greatly in the first minute or so of reconnection. Then you need to disable write caching for your removeable (or all)drives. I'm sorry, I can't remember where this setting is in NT4! Maybe device Manager?

Andy.

 

[THS]

I'll try to find the caching setting, but I guess this setting only has influence on a system that writes to the disk? Is it possible that when a power loss is detected a cache flush is forced even if nothing is in the cache? Is the disk cache flushed after a timeout or when the cache is filled to a surtain level?
My PerfMon-log shows that my system writes to the disk every 5.5 hours. Between two such writings the PerMon-log shows no activity.
From this:

1. Does anyone know of something that may force writings to the disk on power loss?
2. Does anyone know what in NT4.0 that makes the writings to the disk every 5.5 hours? FileMon from Sysinternals do not show any activity.

Best regards
Thomas Solvik