I've followed the instructions to set up a replica server of PostgreSQL with repmgr, But I can't start the PostgreSQL service because of a permission problem.
On the stand by server, I have this on my /etc/repmgr.conf file:
node_id=2
node_name=aws-replica
conninfo='host=<REDACTED> user=repmgr dbname=repmgr port=5432'
data_directory='/mnt/data/postgres/data'
log_file='/var/log/repmgr.log'
As you can see, I've changed the location of the data directory to /mnt/data/postgres/data and also updated the postgresql.conf file with the same information.
When I try to start the PostgreSQL service, I get this error on journalctl:
FATAL: data directory "/mnt/data/postgres/data" has wrong ownership
HINT: The server must be started by the user that owns the data directory.
The folder in question is owned by a normal user, the same one that runs repmgr. If I set the ownership of the folder to postgres:postgres, then repmgr can't perform any operations because it can't access the folder. I tried joining the postgres group, but the service won't start unless the folder has 700 permissions, so it's pointless to join the group.
So, I'm either not being able to start postgresql or repmgr. What can I do to make it work?
The problem was that I created a postgres DB using innitdb, which wasn't necessary. I deleted the database and then ran repmgr as the postgres user, and it worked.
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A slave database was set up some time ago for the purpose of backing up or replicating a remote database. However I can no longer write to the database using a Delphi based ETL (the ETL works for another database pair, but to date has never been used for this particular pair). The replication database was setup by somebody else who has since left the company. I am reasonably sure this has been setup as a replication database, however the employee who has since left told me that replication never worked for unrelated reasons. Using the ETL we can (using SQL queries) read from the one database, and write back to the replication database, Or should be able to, as it is currently read only.
I have tried:
Maintenance such as VACUUM
Attempt to drop tables and the entire database
Restore a full backup from the master database
None of these work, and I am told the database is read-only.
I have looked at postgresql.conf and see that hot_standby is checked, so I think (but am not 100% certain) that the database is in some sort of replication mode (I've never touched replication as supported by Postgres, so I wouldn't know).
I have checked permissions in pg_hba.conf and see there are some credentials in there for replication. I am not sure whether this activates "replication mode" for the database, or simply means these credentials are for replication only.
I have been through months worth of log files (This has not been working since our IT department upgraded the entire network about 5 months ago). I see the log file contents seen below, repeated over and over with nothing else for months. Note the IP address shown below is listed in the pg_hba.conf file, so credentials are valid.
The database is in recovery mode, as I have found by using:
select pg_is_in_recovery();
This explains to me why it's read only, but why can I not restore databases, or just simply dump the entire database and start again (it's a backup so losing/restoring it is not an issue)?
I was tempted to try modifying the recovery.conf file (which exists) but I read/believe that once recovery has been initiated (which in my case it has) modifying the file will have no effect.
I'm using a legacy version of Postgres: 9.2.9
Any help here would be greatly appreciated, as I have been working solidly on this for more than a day now.
Log File entry (sample):
FATAL: could not connect to the primary server:
FATAL: no pg_hba.conf entry for replication connection from host "192.168.20.2", user "postgres", SSL off
FATAL: could not connect to the primary server: server closed the connection unexpectedly
This probably means the server terminated abnormally before or while processing the request.
A couple of options would work for me:
Convert the database from being a read-only replication database, to a standard read/write database or
Dump/drop the entire database so I can create a new one with write capabilities.
It looks like the two database clusters have been set up for replication, but configuration changes on one of the machines broke the replication (changed pg_hba.conf on the primary, changed IP addresses, …).
Here is the way to your desired solutions:
Bringing the standby out of recovery mode: Run
/path/to/pg_ctl promote -D /path/to/data/directory
on the standby as operating system user postgres.
Nuking the standby: Remove the data directory on the standby with rm -rf (or the equivalent on your operating system). Kill all PostgreSQL processes.
Then use initdb to create a new database cluster in the same location.
I have installed postgres 9.5 in my linux(16.04) machine.I have started service using below command.
sudo service postgresql start
This will start postgres service as a postgres user.
But I want to run postgres a different user(myown user).
How can I do .Please help !!.
You have to recursively change the ownership of the database directory to the new user.
If the WAL directory or tablespaces are outside the data directory, you have to change their ownership too.
Then you will have to configure the startup script so that it starts PostgreSQL as the new user. Watch out: if you installed the startup script with an installation package, any changes to it will probably be lost after an update.
I recommend that you don't do all that and continue running PostgreSQL as postgres.
What I am trying to accomplish is a recovery using a continuous archive backup.
I am running a vm of CentOS 6.8 and Postgres 9.1 Postgres 9.1 is the same as the DB that I am pulling from.
I installed Postgres and initialized the DB, started up fine.
Then, following these directions: https://www.postgresql.org/docs/9.3/static/continuous-archiving.html
Stopped the destination pSQL server (as root: service postgresql-9.1 stop)
Copied the destination cluster data folder to the side (as postgres)
Removed the cluster data files (as postgres)
Copied in my source data folder (as postgres)
Copied WAL files into a clean pg_xlog folder under the data folder (as postgres)
Created a recovery.conf file which contained:
restore_command = 'cp /var/lib/pgsql/database_sample_backup/wal_archives/0A/%f %p'
This being another location for the WAL files other than the copy I placed in pg_xlog (was not sure if I needed both)
But when I attempt to restart my server, it fails. (as root: service postgresql-9.1 start)
My pgstartup.log at one point spit out "runuser: cannot set groups: Operation not permitted" but it doesn't consistently do this with every attempt to start.
I've also tried turning off archiving and replication directive in postgres.conf (so that it can run stand alone) and tried copying over the pg_hba.conf from the new DB I had created to see if they would resolve the issue. Neither did.
I've also done a netstat -ntap | grep 5432 which confirmed that I don't have anything else running on the port.
What else can I provide in the form of details, and what else my I attempt in this restoration process.
Thank you for your help!
One of my servers has a virus and the Postgres service in Windows is not running a backup and I'm using Odoo8 and even the Odoo Service is not running.
Is it possible to restore a database using only a OID directory which from what I know is the database file of Postgres.
I assume you mean /data/base/<oid> directory. Unfortunately it's not enough. There are some settings stored outside database oid directory as you called it.
Ex:
/data/glboal/ - cluster users' settings (passwords, roles etc)
/data/pg_xlog/ - WAL entries - possibly with transactions changes not "transfered" to database files yet.
/data/pg_tblspc/ - tablespaces
You need whole /data directory. Read more about PHYSICAL BACKUP.
Edit:
So, if whole /data is available for you, you can restore database to other server. There's one thing you should remember: destination postrges cluster must be at the same varsion ex. 9.4.1. When the first and seccond numbers match (ex 9.2.10 and 9.2.16) this should also work most of the times. Keeping that in mind, you just need to replace /data/ directory on destination server with your source /data directory (destination server must be stopped during that operation).
I apologize for the long post. I have a Postgresql 9.3 server running on a Amazon linux AMI. I also have a compressed dump file from another server which I created using pg_dumpall. Now, I want to restore the data from this dump file in my Postgres. However, I want to load this data into a specific location (say /data).
I'm having a fresh installation of Postgres. So when I tried to do a:
sudo service postgresql93 start
I got an error message asking me to initialize the db. So I did a:
sudo service postgresql initdb
which created the required files in /var/lib/pgsql93/data. After that, I changed the 'data_directory' configuration in /var/lib/pgsql93/data/postgresql.conf and pointed it to /data (I had to do this as root user. I couldn't open the file as the default user).
Now when I try to do a
sudo service postgresql93 start
it fails to start, and when I check the /var/lib/pgsql93/pg_startup.log file, it says:
FATAL: "/data/postgresql" is not a valid data directory
DETAIL: File "/data/postgresql/PG_VERSION" is missing.
So I copied the files from the default (/var/lib/pgsql9.3/data) to /data, changed the permissions to 700 and owner to postgres.
However, when I try to start the service again, it still fails, and in the pgstartup.log, it only says:
LOG: redirecting log output to logging collector process
HINT: Future log output will appear in directory "pg_log".
And when I check the log in /data/pg_log, it says:
LOG: database system was shut down at 2014-12-30 21:31:18 UTC
LOG: database system is ready to accept connections
LOG: autovacuum launcher started
What else could be the problem? I haven't restored the data yet. I just have the files which were created by the initdb command.
#BMW http://www.linuxquestions.org/questions/linux-server-73/change-postgresql-data-directory-649911/ is exactly what I was looking for. Thanks.