For context: this was first reported in the Barman forum here: https://groups.google.com/forum/#!msg/pgbarman/3aXWpaKWRFI/weUIZxspDAAJ They are using Barman for the backups. Stephen Frost wrote: > > But at some point in time, slave became corrupt (one of the base > > files are zero size where it should be 16Mb in size), and IMHO a > > "red alert" should arise - Slave server shall not even startup at > > all. > > How do you know it should be 16Mb in size...? That sounds like you're > describing a WAL file, but you should be archiving your WAL files during > a backup, not just using whatever is in pg_xlog/pg_wal.. It's not a WAL file -- it's a file backing a table. > > Since backups are taken from slave server, all backups are also corrupt. > > If you aren't following the appropriate process to perform a backup > then, yes, you're going to end up with corrupt and useless/bad backups. A few guys went over the backup-taking protocol upthread already. But anyway the backup tool is a moot point. The problem doesn't originate in the backup -- it originates in the standby, from where the backup is taken. The file can be seen as size 0 in the standby. Edson's question is: why wasn't the problem detected in the standby? It seems a valid question to me, to which we currently we don't have any good answer. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
