Bruce Momjian <br...@momjian.us> wrote:
> Kevin Grittner wrote:
 
>> The controller waits for the drive to tell it that it has made it
>> to the platter before it discards it.  What made you think
>> otherwise?
> 
> Because a write-back drive cache says it is on the drive before it
> hits the platters, which I think is the default for SATA drive.
> Is that inaccurate?
 
Any decent RAID controller will ensure that the drives themselves
aren't using write-back caching.  When we've mentioned write-back
versus write-through on this thread we've been talking about the
behavior of the *controller*.  We have our controllers configured to
use write-back through the BBU cache as long as the battery is good,
but to automatically switch to write-through if the battery goes
bad.
 
-Kevin

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