Hi,
My H-Sphere Database is crashed. How I fix it ?

Sometimes PostgreSQL database can get corrupted to the point of no return. That might manifest itself in things like:

hsphere=# VACUUM ;
ERROR: Relation 71343 does not exist

This usually means that index is corrupted.

To recover from the problem:

Login as root:
su –
Stop Postgres if it is running.
Make sure that no Postgres processes are running using the command:
ps auxw | grep post
If any of them are running, kill them.
Remove Postgres’ pid file:
rm -f PGSQL_HOME/data/postmaster.pid
From now on, we note PGSQL_HOME as the Postgres home directory which is /var/lib/pgsql on RedHat servers, and /usr/local/pgsql on FreeBSD.
Switch to Postgres user:
# su – postgres (on RedHat)
# su – pgsql (on FreeBSD)
Backup PostgreSQL database stored in the PGSQL_HOME/data directory:
cp -r PGSQL_HOME/data pgdata.backup
Try to connect to the H-Sphere database in single mode:
postgres -D PGSQL_HOME/data -O -P hsphere
If you get any errors like:

FindExec: found “/usr/bin/postmaster” using argv[0]
2002-03-22 13:42:46 [6002] DEBUG: database system was shut down at 2002-03-22 11:46:11 CET
2002-03-22 13:42:46 [6002] DEBUG: ReadRecord: invalid resource manager id 157 at (0, 561372168)
2002-03-22 13:42:46 [6002] DEBUG: Invalid primary checkPoint record
2002-03-22 13:42:46 [6002] DEBUG: Invalid RMID in secondary checkPoint record
2002-03-22 13:42:46 [6002] FATAL 2: Unable to locate a valid CheckPoint record
2002-03-22 13:42:46 [6002] DEBUG: proc_exit(2)
2002-03-22 13:42:46 [6002] DEBUG: shmem_exit(2)
2002-03-22 13:42:46 [6002] DEBUG: exit(2)
/usr/bin/postmaster: reaping dead processes…
/usr/bin/postmaster: Startup proc 6002 exited with
…
The messages such as:
ReadRecord: invalid resource manager
and other are culprit of the error.

In view of the above errors, do the following:

Execute:
pg_resetxlog PGSQL_HOME/data
(this will reset the write-ahead log and other control information of a PostgreSQL database cluster; they are important but this is the only way to recover).
Try to log into Postgres again in single mode:
postgres -D PGSQL_HOME/data -O -P hsphere
Once you are in, type:
reindex database hsphere;
Exit the database:
q
Finally, start Postgres and see if everything is working.
Here, two Postgres tools are used:
– reindex database to recover corrupted indexes;
– pg_resetxlogs to reset write-ahead log files and the state of Postgres.