Re: restoring a file system backed-up data dir

Richard Broersma Jr <rabroersma(at)yahoo(dot)com> writes:
> I found the correct log file.

> 2006-10-10 04:57:45 PDT% LOG: could not open file "pg_xlog/000000010000000000000055"
> (log file 0, segment 85): No such file or directory
> 2006-10-10 04:57:45 PDT% LOG: could not open file "pg_xlog/000000010000000000000055"
> (log file 0, segment 85): No such file or directory
> 2006-10-10 04:57:45 PDT% LOG: database system was shut down at 2006-09-26 17:11:35 PDT
> 2006-10-10 04:57:45 PDT% LOG: invalid primary checkpoint record
> 2006-10-10 04:57:45 PDT% LOG: invalid secondary checkpoint record
> 2006-10-10 04:57:45 PDT% LOG: logger shutting down
> 2006-10-10 04:57:45 PDT% LOG: startup process (PID 5953) was terminated by signal 6
> 2006-10-10 04:57:45 PDT% PANIC: could not locate a valid checkpoint record

This says that pg_control is out of sync with the pg_xlog files, which
is not real surprising for a filesystem-level backup. You could try
forcing the issue with pg_resetxlog, but you'll very likely end up with
a non-self-consistent database. The pg_dump backup is a better bet.

If you are really desperate to recover the latest changes, try
pg_resetxlog then pg_dump, and diff the dump file against your good
pg_dump to see which changes you want to believe and apply. But I'd
still say you want to initdb and restore from the pg_dump backup before
going forward.

regards, tom lane