Обсуждение: pg_upgrade with link option
I have a question about using pg_upgrade on a very large database. It is not feasible to copy the data location, so I am looking at the link option (pg_upgrade -k). That is, for the same reason it is not practical to run pg_dumpall / restore it is not practical to copy several tens of terabytes of data files during each migration. My two very small tests have failed, no doubt due to my own lack of understanding. I did not have 8.x software on my test computer, so I was testing pg_upgrade using 9.0.2 and 9.0.3.
Goal: in place upgrade of a cluster named test.
Built a clean system with CentOS 5.4 x86_64 and 8 GB RAM (it is running in a VirtualBox VM under Windows 7).
Installed 9.0.2 (PGHOME=/pghome/9.0.2).
Created a cluster with a few million rows of sample data (PGDATA=/pgdata1/test). Just one regular table with one column of type numeric populated with numbers from 1 to 1,000,000. No indexes or other objects.
pg_ctl stop
Installed 9.0.3 (PGHOME=/pghome/9.0.3) including the contrib modules for pg_upgrade and pg_upgrade_support.
su - postgres and try to run initdb per documentation, but failed since the data dir is already populated. Should the documentation be modified to note initdb is not to be run when using pg_upgrade in link mode?
Ran "pg_upgrade -k" with additional flags for the old and new bin dirs, etc. as shown below. Through trial and error I found I must unset certain env. variables. I am setting a number of other variables simply to shorten what must be typed on the command line for the pg_upgrade parameters.
unset PGUSER
unset PGDATABASE
unset PGPORT
unset PGHOME
unset PGVER
export PGCLUSTER1=test
export PGCLUSTER2=test
export PGPORT1=5432
export PGPORT2=5432
export PGDATA1=/pgdata1/test
export PGDATA2=/pgdata1/test
export PGBIN1=/pghome/9.0.2/bin
export PGBIN2=/pghome/9.0.3/bin
cd $PGHOME2
pg_upgrade -k -b $PGBIN1 -B $PGBIN2 -d $PGDATA1 -D $PGDATA2 -p $PGPORT1 -P $PGPORT2
It errors out saying the cluster already has files, which of course is expected since I am using the -k flag.
Aside from the fact that I do not need to use pg_upgrade to do a minor release and this is purely an example, what am I doing wrong? Am I misunderstanding the meaning of the link option? I assume for upgrade in place the old and new cluster are the same thing, just the binaries are different. I also assume env. variables are allowed and you are not opening other windows/sessions.
-Mark
Mark Johnson wrote: > I have a question about using pg_upgrade on a very large database. It is not feasible to copy the data location, so I amlooking at the link option (pg_upgrade -k). That is, for the same reason it is not practical to run pg_dumpall / restoreit is not practical to copy several tens of terabytes of data files during each migration. My two very small testshave failed, no doubt due to my own lack of understanding. I did not have 8.x software on my test computer, so I wastesting pg_upgrade using 9.0.2 and 9.0.3. > Goal: in place upgrade of a cluster named test. > Built a clean system with CentOS 5.4 x86_64 and 8 GB RAM (it is running in a VirtualBox VM under Windows 7). > Installed 9.0.2 (PGHOME=/pghome/9.0.2). > Created a cluster with a few million rows of sample data (PGDATA=/pgdata1/test). Just one regular table with one columnof type numeric populated with numbers from 1 to 1,000,000. No indexes or other objects. > pg_ctl stop > Installed 9.0.3 (PGHOME=/pghome/9.0.3) including the contrib modules for pg_upgrade and pg_upgrade_support. > su - postgres and try to run initdb per documentation, but failed since the data dir is already populated. Should the documentationbe modified to note initdb is not to be run when using pg_upgrade in link mode? > Ran "pg_upgrade -k" with additional flags for the old and new bin dirs, etc. as shown below. Through trial and error Ifound I must unset certain env. variables. I am setting a number of other variables simply to shorten what must be typedon the command line for the pg_upgrade parameters. > unset PGUSER > unset PGDATABASE > unset PGPORT > unset PGHOME > unset PGVER > export PGCLUSTER1=test > export PGCLUSTER2=test > export PGPORT1=5432 > export PGPORT2=5432 > export PGDATA1=/pgdata1/test > export PGDATA2=/pgdata1/test > export PGBIN1=/pghome/9.0.2/bin > export PGBIN2=/pghome/9.0.3/bin > cd $PGHOME2 > pg_upgrade -k -b $PGBIN1 -B $PGBIN2 -d $PGDATA1 -D $PGDATA2 -p $PGPORT1 -P $PGPORT2 > It errors out saying the cluster already has files, which of course is expected since I am using the -k flag. > Aside from the fact that I do not need to use pg_upgrade to do a minor release and this is purely an example, what am Idoing wrong? Am I misunderstanding the meaning of the link option? I assume for upgrade in place the old and new clusterare the same thing, just the binaries are different. I also assume env. variables are allowed and you are not openingother windows/sessions. > -Mark You have shown a lot of text above, but not the error message you got. Can I see that please? -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. +
On Thu, Mar 10, 2011 at 1:30 PM, Bruce Momjian <bruce@momjian.us> wrote: > Mark Johnson wrote: >> export PGPORT1=5432 >> export PGPORT2=5432 >> export PGDATA1=/pgdata1/test >> export PGDATA2=/pgdata1/test >> export PGBIN1=/pghome/9.0.2/bin >> export PGBIN2=/pghome/9.0.3/bin ISTM you need to change the pgdata and pgport for the second cluster, as they will both need to run simultaneously during the upgrade process. > > You have shown a lot of text above, but not the error message you got. > Can I see that please? > Agree with Bruce, showing us any error messages would be helpful. Robert Treat play: xzilla.net work: omniti.com hiring: l42.org/lg
Robert Treat wrote: > On Thu, Mar 10, 2011 at 1:30 PM, Bruce Momjian <bruce@momjian.us> wrote: > > Mark Johnson wrote: > >> export PGPORT1=5432 > >> export PGPORT2=5432 > >> export PGDATA1=/pgdata1/test > >> export PGDATA2=/pgdata1/test > >> export PGBIN1=/pghome/9.0.2/bin > >> export PGBIN2=/pghome/9.0.3/bin > > ISTM you need to change the pgdata and pgport for the second cluster, > as they will both need to run simultaneously during the upgrade > process. Oh, yikes. I know you can share tablespaces between old and new servers, except for an upgrade of the same major version, which is what we are doing here. You can never share data directories. --------------------------------------------------------------------------- > > > > > You have shown a lot of text above, but not the error message you got. > > Can I see that please? > > > > Agree with Bruce, showing us any error messages would be helpful. > > > Robert Treat > play: xzilla.net > work: omniti.com > hiring: l42.org/lg -- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. +