Scott Marlowe wrote: > On Sat, May 9, 2015 at 11:20 PM, Albe Laurenz <laurenz.albe@xxxxxxxxxx> wrote: >> Maxim Boguk wrote: >>> It's depend where a corruption happen, if pages become corrupted due to some >>> problems with physical storage (filesystem) in that case a replica data should be ok. >> I would not count on that. >> I have had a case where a table file got corrupted due to hardware problems. >> Pages that contained data were suddenly zeroed. >> PostgreSQL recognizes such a block as empty, so the user got no error, but >> data were suddenly missing. What does a user do in such a case? He/she grumbles >> and enters the data again. This insert will be replicated to the standby (which was >> fine up to then) and will cause data corruption there (duplicate primary keys). > You had zero corrupted pages turned on. PostgreSQL by default does NOT > DO THIS. That setting is for recovering a corrupted database not for > everyday use! No, I didn't. It was not PostgreSQL that zeroed the page, but the hardware or operating system. The problem was a flaky fibre channel cable that intermittently was connected and disconnected. That corrupted the file system, and I guess it must have been file system recovery that zeroed the pages. I'm not 100% certain, at any rate the symptoms were silently missing data. Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
