On Oct 13, 2006, at 14:36 , Joshua D. Drake wrote:
Stephen Frost wrote:
* Alexander Staubo (alex@xxxxxxxxxxxxxxx) wrote:
What formula did you use to get to that number? Is there a generic
way on Linux to turn off (controller-based?) write caching?
Just a side-note, but if you've got a pretty good expectation that
you
won't be without power for 24 consecutive hours ever you can get a
controller with a battery-backed write cache (some will do better
than
24 hours too). For the performance concerned... :)
No to mention if you are *that* concerned you could buy a generator
for
500 bucks that will keep the machine alive if you absolutely have to.
There is nothing wrong with write back cache as long as you have the
infrastructure to support it.
Why does the battery have to be at that level? It's seems like a
reasonable poor man's solution would be to have a standard $50 UPS
plugged in and have the UPS signal postgresql to shut down and sync.
Then, theoretically, it would be safe to run with fsync=off. The
level of risk seems the same no?
-M
