ZFS-FreeBSD + postgresql performance

[Michael Schmiedgen]

On 10/23/13 19:14, Mark Felder wrote:
> On Wed, Oct 23, 2013, at 11:25, Albert Shih wrote:
>> My question is about the performance, I known ZFS eat all memory he can
>> have (or almost), so what append when we run database like postgresql and
>> jail ? (it's also the reason of 96 Go ram).
>>
>> Sorry for cross-posting but it's about 3 differents things....
>>
>
> To my understanding the solution is to change the primarycache to
> "metadata" for any ZFS filesystem that you do not want ZFS to heavily
> cache in memory.
>
> Example:
>
> # zfs set primarycache=metadata tank/usr/local/pgsql

In addition to this it is recommended to set the recordsize
to the fixed value of 8k on dataset creation.

Michael