On 04/09/2018 08:29 PM, Mark Dilger wrote:
>
>> On Apr 9, 2018, at 10:26 AM, Joshua D. Drake <jd@commandprompt.com> wrote:
>
>> We have plenty of YEARS of people not noticing this issue
>
> I disagree. I have noticed this problem, but blamed it on other things.
> For over five years now, I have had to tell customers not to use thin
> provisioning, and I have had to add code to postgres to refuse to perform
> inserts or updates if the disk volume is more than 80% full. I have lost
> count of the number of customers who are running an older version of the
> product (because they refuse to upgrade) and come back with complaints that
> they ran out of disk and now their database is corrupt. All this time, I
> have been blaming this on virtualization and thin provisioning.
>
Yeah. There's a big difference between not noticing an issue because it
does not happen very often vs. attributing it to something else. If we
had the ability to revisit past data corruption cases, we would probably
discover a fair number of cases caused by this.
The other thing we probably need to acknowledge is that the environment
changes significantly - things like thin provisioning are likely to get
even more common, increasing the incidence of these issues.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services