Re: root cause of corruption in hot standby

Well I've verified my primary backups are working, and think my plan is to
patch to 9.5.14, reprime a replica in the same environment and see how it
goes unless someone has an idea of something to check on the host to avoid
future corruption...

On Thu, Sep 6, 2018 at 12:28 PM Mike Broers <mbroers(at)gmail(dot)com> wrote:

> So I have discovered corruption in a postgres 9.5.12 read replica, yay
> checksums!
>
> 2018-09-06 12:00:53 CDT [1563]: [4-1] user=postgres,db=production
> WARNING: page verification failed, calculated checksum 3482 but expected
> 32232
>
> 2018-09-06 12:00:53 CDT [1563]: [5-1] user=postgres,db=production ERROR:
> invalid page in block 15962 of relation base/16384/464832386
>
> The rest of the log is clean and just has usual monitoring queries as this
> isnt a heavily used db.
>
> This corruption isnt occurring on the primary or a second replica, so I'm
> not freaking out exactly, but Im not sure how I can further diagnose what
> the root cause of the corruption might be.
>
> There were no power outages. This is a streaming hot standby replica that
> looks like it was connected fine to its primary xlog at the time, and not
> falling back on rsync'ed WALS or anything. We run off an SSD SAN that is
> allocated using LVM and I've noticed documentation that states that can be
> problematic, but I'm unclear on how to diagnose what might have been the
> root cause and now I'm somewhat uncomfortable with this environments
> reliability in general.
>
> Does anyone have advice for what to check further to determine a possible
> root cause? This is a CentOS 7 vm running on Hyper-V.
>
> Thanks for any assistance, greatly appreciated!
> Mike
>
>