Thread: pg_clog and pg_xlog empty, postgresql refuses to start
First things first: Postgresql 8.4.2 on Fedora Core 2 X86. Something seems to have happened to my pg_xlog and pg_clog directories after (I believe) a power outage. In the course of trying to figure out why the server wouldn't start, I cleaned out pg_clog and pg_xlog, in an obviously vain attempt to reset things. I was under the impression that the server could start without those files. Now I seem to be stuck. So now what? Here is what postmaster has to say on the subject: LOG: database system was shut down at 2004-08-16 15:52:01 PDT LOG: could not open file "/usr/local/var/lib/pgsql32-broken/pg_xlog/0000000F000000F3" (log file 15, segment 243): No such file or directory LOG: invalid primary checkpoint record LOG: could not open file "/usr/local/var/lib/pgsql32-broken/pg_xlog/0000000F000000F3" (log file 15, segment 243): No such file or directory LOG: invalid secondary checkpoint record PANIC: could not locate a valid checkpoint record LOG: startup process (PID 9920) was terminated by signal 6 LOG: aborting startup due to startup process failure Thx Glen Parker
"Glen Parker" <glenebob@nwlink.com> writes:
> First things first: Postgresql 8.4.2 on Fedora Core 2 X86.
I take it this message fell through a time warp ;-)
> Something seems to have happened to my pg_xlog and pg_clog directories after
> (I believe) a power outage. In the course of trying to figure out why the
> server wouldn't start, I cleaned out pg_clog and pg_xlog, in an obviously
> vain attempt to reset things. I was under the impression that the server
> could start without those files. Now I seem to be stuck.
That was probably not your best first move...
I'd put back the clog files if at all possible. If not you can
substitute zero-filled 256K files for each clog file the server
complains about not finding, but realize that you *will* be losing
transactions in whole or in part.
As for pg_xlog, you can cons up dummy xlog contents with pg_resetxlog,
but again you'd be better off with the real thing. The dummy files will
not be capable of replaying whatever happened since your last checkpoint.
What failures were you getting *before* you decided to try this?
regards, tom lane
> > First things first: Postgresql 8.4.2 on Fedora Core 2 X86. > > I take it this message fell through a time warp ;-) Yep :-) 7.4.2. >> ...I cleaned out pg_clog and pg_xlog... > > That was probably not your best first move... This is actually a development copy of our real database, so worst-case scenario is a dump/restore. No big deal. > I'd put back the clog files if at all possible. If not you can > substitute zero-filled 256K files for each clog file the server > complains about not finding, but realize that you *will* be losing > transactions in whole or in part. > > As for pg_xlog, you can cons up dummy xlog contents with pg_resetxlog, > but again you'd be better off with the real thing. The dummy files will > not be capable of replaying whatever happened since your last checkpoint. OK, all the files I deleted, I really deleted... See? I'm on a roll today. pg_resetxlog did the trick, mostly; the server starts again and I seem to be back to where I started... > What failures were you getting *before* you decided to try this? I started out, and am now once again, getting this error when issuing a delete query in psql: ERROR: could not access status of transaction 655360 DETAIL: could not read from file "/usr/local/var/lib/pgsql32/pg_clog/0000" at offset 163840: Success I am now also getting this error when vacuuming a different table: ERROR: catalog is missing 2 attribute(s) for relid 25297932 Hmm, whatever happened over the weekend that caused this machine to be *off* this morning must have been a bit nasty... Dump/restore may be my only option. Thx again, Glen Parker
"Glen Parker" <glenebob@nwlink.com> writes:
> I am now also getting this error when vacuuming a different table:
> ERROR: catalog is missing 2 attribute(s) for relid 25297932
Yeah, this is what I warned you about: partial committal of transactions.
Given that it's only a devel server, it's probably best to initdb ...
regards, tom lane