NetApp NFS vs. ZFS and NFS for Maildir

Stephan von Krawczynski
Mon, 14 Mar 2016 08:49:46 -0000

On Mon, 14 Mar 2016 16:59:28 +1000
Noel Butler <noel.butler at ausics.net> wrote:

> On 14/03/2016 09:59, Stephan von Krawczynski wrote:
> > On Mon, 14 Mar 2016 09:32:42 +1000
> > Noel Butler <noel.butler at ausics.net> wrote:
> >
> >> On 13/03/2016 20:47, Stephan von Krawczynski wrote:
> >> > On Sun, 13 Mar 2016 09:45:06 +0000
> >> > James <lista at xdrv.co.uk> wrote:
> >> >
> >> >> On 11/03/2016 15:17, Stephan von Krawczynski wrote:
> >> >>
> >> >>  > zfs set sync=disabled ?
> >> >>
> >> >> Only if you are happy to loose data on power failure.
> >> >
> >> > I don't know the actual setup, but if you have no UPC you
shouldn't
> >> > host email
> >> > services anyway.
> >>
> >> I'm guessing you meant UPS, anyway, a UPS wont protect you
from human
> >> error.
> >>
> >> Also, most buildings, at least in this country, have a fire
emergency
> >> shutoff requirement, meaning mains is isolated from the building,
and
> >> the back up gennies are also forbidden to be engaged - UPS's
dont last
> >> forever.
> >
> > Guys, please don't argue on kindergarten level. The UPS is for
backing
> > a
> > sudden death, but not for running five days. Of course you can do a
> > controlled
> > shutdown if battery level falls below a trigger value. And this is
> > about all
> > you need: control. There is no fs error as long as you perform a
> > regular
>
> and you've never seen these cause problems with FS?  then you must be a
> newbie, in over 25 years I've seen it happen several times - yes even
> after an apparent controlled shutdown.

Maybe you're doing something wrong then. because in my last 21 years working
exactly in this business I've not seen a single deadly fs-crash because of a
power-outage. Not one. And we had of course several, all backed by UPS.

> > shutdown. If UPS-backup is forbidden in your country then I suggest
> > moving to
> > civilized regions of the planet ;-)
>
> Now whos on kindergarten level, do you really want fireman pouring water
> on fire on a level of a building thats powered up because some lamer has
> a generator running? really? I'm sure those firemen would gladly hand
> YOU the hose, the best UPS systems runtime we've seen under average
load
> for a large ISP data centre is 21 mins, usually ample time to allow the
> generators to start up, come to full power, and switch in taking over
> the load, but thats not going to help during a building fire, once their
> depleted, their depleted.

If your servers get drowned with water during a fire your fs is probably the
least of your worries. You don't really plan to re-enable servers with
water- or fire-damage, do you? That's probably why there shouldn't be a
fireman pouring water in the first place.
Please lets stop this here as it has pretty much nothing to do with dovecot...

--
Regards,
Stephan