On 04/11/12 23:28, Nyamul Hassan wrote:
> Upon inspecting the hard drive, we were able to salvage the "data"
> folder, but when we try to load it into the PGSQL version of the data
> folder (8.2), the server would not load. Upon closer inspection, we
> suspect the culprit to be the file 0015 in pg_clog which is 214kb
> instead of 256kb size of all other files in the same folder.
>
> Is there any way that we can salvage the data from this data folder?
1. Make sure you have a complete backup of all of the data dir (pg_xlog,
clog - everything) before making any changes.
This one is vital. Don't skip it. Any fixes you attempt may end up
making things worse.
2. What is the exact error-message you get when trying to start up
PostgreSQL?
When starting the server, try doing it directly in single-user mode
until everything is up and running
http://www.postgresql.org/docs/8.2/static/app-postgres.html
3. Have a quick read of the blog-post below as a start point explaining
the various files.
It's a useful introduction and can give you some keywords to search
against.
http://it.toolbox.com/blogs/database-soup/pg_log-pg_xlog-and-pg_clog-45611
4. You may end up needing the resetxlog tool, but don't just blindly run it:
http://www.postgresql.org/docs/8.2/static/app-pgresetxlog.html
5. Version 8.2 is end-of-life since 2011.
Once your database is working again, dump the data and upgrade as
soon as possible.
Until you upgrade, make sure you have the last release of 8.2.23
running.
6. Obviously, make sure backups are scheduled regularly.
It may well be that you can get things up and running by just padding
pg_log/0015 to 256KB with zeroes. That doesn't mean your database will
be 100% consistent though - transaction information will have been lost.
But before you do anything drastic, do steps #1 and #2.
--
Richard Huxton