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 shutdown. If UPS-backup is forbidden in your country then I suggest moving to civilized regions of the planet ;-) -- Regards, Stephan
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 > regularand 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.> 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 you have the urge to reply to all rather than reply to list, you best first read http://members.ausics.net/qwerty/
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