recommended memory for zfs

[Tom Evans]

On Thu, May 9, 2013 at 2:18 PM, Benjamin Adams <benjamindadams at gmail.com> wrote:
> Hello zfs question about memory.
> I heard zfs is very ram hungry.
> Service looking to run:
> - nginx
> - postgres
> - php-fpm
> - python
>
> I have a machine with two quad core cpus but only 4 G Memory
>
> I'm looking to buy more ram now.
> What would be the recommend amount of memory for zfs across 6 drives on this
> setup?
>

There is no right answer to this question. ZFS does not use a lot of
RAM, but it will use as much as you allow as cache (in the ARC). How
much data is your working set? How much of your working set do you
need to keep in cache? You need that much memory (plus whatever to run
your applications).

>
> Also can 9.1 now boot to zfs from the installer?
> (no tricks for post install)
>

Can you clarify? The installer still cannot setup zfs pools, you must
do so manually (but then can return to the installer).

Cheers

Tom