Bruce Momjian <bruce@xxxxxxxxxx> 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 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
