On Thu, Jul 26, 2012 at 3:39 AM, Manoj Agarwal <ma@xxxxxxxxx> wrote: > Hi, > > > > I have two virtual machines with two different versions of Postgresql. One > machine contains Postgres 7.4.19 and another has Postgres 8.4.3. I also > have other instances of these two virtual machines. I need to transfer the > database from one machine to other. Both machines contain a database with > the same name, for example: testdb, but with different data/values, but the > structure is exactly same. > > > > I want to do the following: > > · Take file system level backup from from first machine for > Postgres database ‘testdb’ and restore it in another instance that has SAME > version of Postgres. i.e. backup the database ‘testdb’ from Postgres 7.4.19 > and restore it on another virtual machine with same Postgres version 7.4.19. > > · Take file system level backup from from first machine for > Postgres database ‘testdb’ and restore it in another instance that has > DIFFERENT version of Postgres. i.e. backup the database testdb from > Postgres 7.4.19 and restore it to another virtual machine with different > Postgres version 8.4.3. > > > > I can achieve it with pg_dump and pg_restore, but not with file level > backups. The data directory is /var/lib/pgsql/data that contains base > directory amongst others, that contains directories for each database > referred to by their OIDs. If I replace the complete data directory of one > machine from the instance of another machine (with same or different > Postgres version), It is failing to identify OIDs for that database. > > > > It should be possible in Postgres to swap two data directories in two > different virtual machines without requiring pg_dump and pg_restore. With > me, it doesn’t work in both the cases mentioned above. In first case, it > gives an error of missing OID for the database. In second case, it is > giving version incompatibility issue. > > > > Is there a way in Postgres to do file system level backup? The objective is > to push /var/lib/pgsql/data directory across different virtual machines, > without the need to backup and restore Postgres database with ‘pg_dump’ and > ‘pg_restore’ commands. Any help will be highly appreciated. You definitely cannot take a filesystem level backup from one version and throw it into a different version (perhaps minor versions, but not 7.x vs. 8.x). This is basically what pg_upgrade was created to solve (however with a different purpose). But pg_upgrade definitely doesn't support 7.x, and I'm not even sure that it supports 8.x. In fact, I don't even know that 7.x is a supported version of postgresql in any context any longer. As for the issue of moving a filesystem level backup between identical versions, I believe that should work (although I have no clue if there were bugs preventing this in a version as old as 7.x). Can you provide exact details & commands of what you're trying to do, and the exact errors you're seeing? -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
