Re: ZFS/RAIDZ and SAMBA: abyssimal performance

Fabian Keil wrote:
> Fleuriot Damien <ml_at_my.gd> wrote:
> 
> >
> > On Jan 4, 2013, at 4:19 PM, O. Hartmann
> > <ohartman_at_zedat.fu-berlin.de> wrote:
> >
> > > Am 01/04/13 15:45, schrieb Garrett Cooper:
> > >> On Fri, Jan 4, 2013 at 6:06 AM, Fleuriot Damien <ml_at_my.gd> wrote:
> > >>
> > >> ...
> > >>
> > >>> And this is under [global] in /usr/local/etc/smb.conf:
> > >>>   min receivefile size = 16384
> > >>>   aio read size = 16384
> > >>>   aio write size = 16384
> > >>>   aio write behind = yes
> > >>
> > >> These are still pretty low, depending on what your
> > >> networking/disk
> > >> setup is like; my important performance settings are:
> > >>
> > >>        socket options = SO_RCVBUF=64240 SO_SNDBUF=64240
> > >>        TCP_NODELAY
> > >> IPTOS_LOWDELAY IPTOS_THROUGHPUT
> > >>        write cache size = 65536
> > >>        aio read size = 65536
> > >>        aio write size = 65536
> > >>        directory name cache size = 0
> 
> > > Well, now I have peak values ~ 120 MB/s when copying. I applied
> > > Fleuriot
> > > Damien's values to /boot/loader.conf and yours to the smb.conf.
> > > Somewhere in the handbook this should be documented! it is to much
> > > efford to get SAMBA working properly with ZFS, if the tricks and
> > > problems are so widespread over several architectural aspects of
> > > the system.
> > >
> > > It could save a lot of time for adminsitartors and those which try
> > > FreeBSD as a serving system instead of Linux.
> > >
> > > Just for the record. I feel a bit confused about all the tricks
> > > and
> > > tweak now "published" for ZFS, its magic L2ARC, the kernel_vmem
> > > wizzardy
> > > thingis. The ZFS Wiki seems to be a bit outdated and confusing, it
> > > would
> > > be a great deal if all these things could be lined up a s a primer
> > > with
> > > a bit more explanations than "put this number there".
> 
> > The problem, Oliver, is that these values are system dependant.
> 
> While I agree that the values are system dependant the purpose of
> the tunables could still be documented together with a description
> of how to properly test that they have any effect at all and that
> it's an improvement compared to the defaults.
> 
What about capturing a few examples, like this one for a system with
16Gb of Ram. Basically cases of:
- this is my hardware config and here's what works well for me
It's pretty easy for people to choose the example closest to their
setup as a starting point.

Then urls to where the docs are, so people can read/fine tune from there?

rick


rick

> Scarce ZFS tuning documentation is also a problem upstream which
> probably doesn't help.
> 
> Fabian