Re: Maximum transaction rate

On Fri, Mar 6, 2009 at 2:22 PM, Ben Chobot <bench@silentmedia.com> wrote:
> On Fri, 6 Mar 2009, Greg Smith wrote:
>
>> On Fri, 6 Mar 2009, Tom Lane wrote:
>>
>>>  Otherwise you need to reconfigure your drive to not cache writes.
>>>  I forget the incantation for that but it's in the PG list archives.
>>
>> There's a dicussion of this in the docs now,
>> http://www.postgresql.org/docs/8.3/interactive/wal-reliability.html
>
> How does turning off write caching on the disk stop the problem with LVM? It
> still seems like you have to get the data out of the OS buffer, and if
> fsync() doesn't do that for you....

I think he was saying otherwise (if you're not using LVM and you still
have this super high transaction rate) you'll need to turn off the
drive's write caches.  I kinda wondered at it for a second too.