======PostgreSQL server won't start due to damaged log files======

If the PostgreSQL server won't start at all, because its transaction logs are damaged, you will probably need to recreate the database store totally.

To rebuild the database:
  - Open a command prompt and find the VPOP\pgsql folder
  - Rename the **data** folder to **data_old**
  - Run <code>bin\initdb -D <VPOP3folder>\pgsql\data -U postgres -W -A md5</code>
  - When it prompts for a password, type in the password you want for the PostgreSQL superuser - we use **pgsqlpass**. If you choose to use something different, make sure you remember what it is!
  - Type <code>copy data_old\postgresql.conf data</code><code>copy data_old\vpop3db.conf data</code><code>copy data_old\vpop3dbuser.conf data</code> to copy the database server configuration to the new location. You may be prompted if you want to overwrite the existing file. If so, confirm the overwrite.
  - Set the permissions on the new Data folder. In Windows Explorer, right-click the VPOP3\pgsql\DATA folder and choose 'Properties' -> 'Security'. Check that the 'vpop3postgres' user ('postgres' user in VPOP3 versions 3 and 4) has 'Full control' of the folder.
  - Start the PostgreSQL service in Windows
  - From the command prompt in vpop3\pgsql\bin run <code>createuser -S -D -R -U postgres -P vpop3</code>At the 'Enter Password for new role' and 'Enter it again' prompts type **vpop3pass**. At the 'Password:' prompt type **pgsqlpass** (or whatever password you defined in the step 4 above)
  - [[restore a backup of VPOP3|Restore the latest good database backup]]

Once you're happy everything is working OK, you can delete the **data_old** folder.

If you wish, we can remote into your server and try to recover the data for you, but there will be a [[http://www.pscs.co.uk/buynow/buy.php?item=MISCSUP3|£75 charge]] for this. You can [[support@pscs.co.uk|email us]] or phone on +44 1484 855800 to arrange this.

=====Possible Causes=====
The most common causes of this type of corruption are some third party software accessing the pgsql\data folder files - usually a virus scanner or backup or file synchronisation program. Backup programs using the Windows 'volume snapshot' (VSS) service are OK to access the pgsql\data folder, other backup programs should always be excluded from the pgsql\data folder.

Note that if you use a backup program which doesn't use VSS, even if it does a copy of the pgsql\data folder without causing any problems, that copy will not be usable, so there is no point doing it. See here for how to [[http://wiki.pscs.co.uk/how_to%3Bbackup_vpop3#manual_database_backup|backup the database correctly]]

The only files in the pgsql\data folder which should ever be accessed by anything other than PostgreSQL itself are the contents of the ''pg_log'' folder (NOT the pg_xlog/pg_clog folders!) or the ''*.conf'' files.


====Possible alternative solution====
You **may** be able to use the **[[http://www.postgresql.org/docs/8.3/static/app-pgresetxlog.html|pg_resetxlog.exe]]** program to create new transaction logs and control files which are 'just good enough' to get PostgreSQL started again, then you can [[http://wiki.pscs.co.uk/how_to%3Bbackup_vpop3#manual_database_backup|backup the database]] before doing the following steps. (Do //not// use pg_resetxlog.exe, then continue using the database without doing a full backup/rebuild/restore, corruption may be hidden, and cause bigger problems in the future). See the [[http://www.postgresql.org/docs/8.3/static/app-pgresetxlog.html|pg_resetxlog instructions]] for details on how to use that utility.