Hi, I actually run with 2 posmasters, 7.2 & 7.4 with different "physical" /var/lig/pgsql/data & /var/lig/pgsql/data2 with no problem. They have different TCP/IP port and run well. The $PG_DATA$ is not needed if you use "pg_ctl -D" form, so you can run many postmaster at same times. A question about that, there is an utility to use 2 different postmaster in production with same version ? regards, > Clay Luther wrote: > > I am wondering if it is possible, or even advisable, to run two > postmasters on a single system. > > For example, we have an embedded system with a normal runtime > partition (called the "A") in which the PGDATA is /var/lib/pgsql/data. > We also have a offline partition which is a copy of the runtime > partition, but is mounted under /partB -- PGDATA here is > /partB/var/lib/pgsql/data. > > During upgrades, we will alter the installation on the B partition, > then swap the paritions after a reboot. > > However, during upgrades, we may need to migrate data from the A > partition databases to the B partition databases. > > For database migrations, I was hoping I could do the following > (remember, a postmaster is already running on /var/lib/pgsql/data): > > 1) Alter the the postgresql.conf of the B partition PGDATA, setting > the tcp/ip port to 54321. > 2) Start the "B" postmaster, pg_ctl -D /partB/var/lib/pgsql/data start > 3) Use ODBC/JDBC to perform necessary migration from A databases to B > databases. > 4) pg_ctl -D /partB/var/lib/pgsql/data stop > 5) Set B postgresql.conf tcp/ip port to 5432. > 6) Reboot (higher level systems will automatically swap the A and B > partitions, so B becomes A and A becomes the new B). > > Conceptually clear, but I wanted to know if there was anything I > needed to be worried about. > > Thanks. > > --- > Clay > claycle@cisco.com > (972) 813-5004 > > ---------------------------------------------------------------------- > I've stopped 272 spam messages. You can too! > One month FREE spam protection at www.cloudmark.com > [Cloudmark SpamNet - Join the fight against spam!] > ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
