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
