On 20.04.2016 12:10, Andreas Joseph Krogh wrote:
På onsdag 20. april 2016 kl. 11:02:31, skrev Alex Ignatov
<a.igna...@postgrespro.ru <mailto:a.igna...@postgrespro.ru>>:
On 20.04.2016 11:40, Andreas Joseph Krogh wrote:
På onsdag 20. april 2016 kl. 10:33:14, skrev Alex Ignatov
<a.igna...@postgrespro.ru <mailto:a.igna...@postgrespro.ru>>:
On 20.04.2016 11:29, Devrim Gündüz wrote:
> Hi,
>
> On Wed, 2016-04-20 at 10:43 +0300, Alex Ignatov wrote:
>> Today in Big Data epoch silent data corruption becoming
more and more
>> issue to afraid of. With uncorrectable read error rate ~
10^-15 on
>> multiterabyte disk bit rot is the real issue.
>> I think that today checksumming data must be mandatory
set by default.
>> Only if someone doesn't care about his data he can
manually turn this
>> option off.
>>
>> What do you think about defaulting --data-checksums in initdb?
> I think this should be discussed in -hackers, right?
>
> Regards,
May be you right but i want to know what people think about
it before
i'll write to hackers.
-1 on changing the default.
10^15 ~= 1000 TB, which isn't very common yet. Those having it
probably are aware of the risk and have enabled checksums already.
--
*Andreas Joseph Krogh*
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andr...@visena.com <mailto:andr...@visena.com>
www.visena.com <https://www.visena.com>
<https://www.visena.com>
It is per bit not bytes. So it is ~100 TB. We working with some
enterprise who have WALs creation rate ~ 4GB per min - so it is
only max 100 days before you get bit rotted and have probability
to get silent data corruption.
Also don't forget that it is theoretical limit and Google tells us
that HDD and SSD is not as reliable as manufactures tell. So this
10^-15 can easily be much higher.
Ok, but still - the case you're describing isn't the common-case for
PG-users. Enterprises like that certainly chould use --data-checksums,
I'm not arguing against that, just that it shouldn't be the
default-setting.
--
*Andreas Joseph Krogh*
CTO / Partner - Visena AS
Mobile: +47 909 56 963
andr...@visena.com <mailto:andr...@visena.com>
www.visena.com <https://www.visena.com>
<https://www.visena.com>
Why do you think that common pg-users doesn't care about their data?
Also why do we have wal_level=minimal fsync=on and other stuff?
--
Alex Ignatov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
