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
On 14/03/2016 18:49, Stephan von Krawczynski wrote:> >> >> 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.Consider yourself lucky, Most network admins whove been around large busy ISP DC's have seen this in their lifetime, to not have seen one is rare, go buy yourself a lotto ticket :)> > 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.This shows you dont understand structural engineering, the fire does not have to be on your floor, it can be far away as two or so levels above, with the high pressure water used - equating to a shitload of water, there are ducts, shafts, other risers and so on that with a shit-tone of water can easily penetrate fireblocks of floors below - dont take my work, go ask a fireman, or maybe watch the nightly news sometime (building fire - many levels water affected blah blah blah)... so keeping those boxes on via UPS's is asking for lots of charcoaled boards and fried drives. IOW, total stupidity. Should those machines be depowered as required by our building codes, well, might take a few days of drying out but at least they will power back up without error - yes, done it in risk assessments. -- If you have the urge to reply to all rather than reply to list, you best first read http://members.ausics.net/qwerty/
On Sat, 19 Mar 2016 17:37:04 +1000 Noel Butler <noel.butler at ausics.net> wrote:> On 14/03/2016 18:49, Stephan von Krawczynski wrote: > > > >> > >> 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. > > Consider yourself lucky, Most network admins whove been around large > busy ISP DC's have seen this in their lifetime, to not have seen one is > rare, go buy yourself a lotto ticket :) > > > > > 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. > > This shows you dont understand structural engineering, the fire does not > have to be on your floor, it can be far away as two or so levels above, > with the high pressure water used - equating to a shitload of water, > there are ducts, shafts, other risers and so on that with a shit-tone of > water can easily penetrate fireblocks of floors below - dont take my > work, go ask a fireman, or maybe watch the nightly news sometime > (building fire - many levels water affected blah blah blah)... so > keeping those boxes on via UPS's is asking for lots of charcoaled boards > and fried drives. IOW, total stupidity. > > Should those machines be depowered as required by our building codes, > well, might take a few days of drying out but at least they will power > back up without error - yes, done it in risk assessments.Obviously you must work for people that have not the slightest idea about using hardware in a correct way and don't know when the time has come to throw it away. Man, there is no way to let a drowned box survive. It is not back to normal when it is dry. If you don't get that I am pretty happy to be no customer. This can only be an idea born in the sick mind of a controller who didn't want to pay insurance in the first place. We are talking about serious corrosion effects here let alone that you have a hard time even knowning when your boxes are really dry. Your fireman on the other hand seem to be stuck in the 80ths. Today there are solar panels almost everywhere _which you cannot turn off_. Sure you have a switch somewhere, but it does not help you for the space between the switch and the roof (which can be a pretty long distance). Really, sorry, I don't want to listen to more horror stories from you operating drowned equipment. And in the end: considering your "large busy ISP DC's" they should have backup DCs located elsewhere with mirrored data, right? Lets please end that now and for all. -- Regards, Stephan