I tried many times with different options of rsync :
with rsync -a as explained in the wiki (http://www.postgresql.org/docs/9.0/interactive/warm-standby.html#STANDBY-SERVER-SETUP), it takes 1h40 for each distant slave and quite all data files are transferred
with -c (checksum) or -z (compress) , it takes more time, probably due to checksum time or compress/uncompress time
For example, the rsync commands I am using are for data and logs are (I have 2 databases, 1 tablespace per database):
rsync -a /var/opt/hosting/db/slony/pg_xlog/* slave-db01.profiles.bench.pns-si.s1.p.fti.net:/var/opt/hosting/db/slony/pg_xlog/
rsync -a /var/opt/hosting/db/profiles/bench/* slave-db01.profiles.bench.pns-si.s1.p.fti.net:/var/opt/hosting/db/profiles/bench/
rsync -a /var/opt/hosting/db/profiles/profiles/* slave-db01.profiles.bench.pns-si.s1.p.fti.net:/var/opt/hosting/db/profiles/profiles/
More information about version of rsync :
jaluce@master-db01:~$ rsync --version
rsync version 3.0.7 protocol version 30
Jal
2011/11/14 Cédric Villemain <cedric.villemain.debian@xxxxxxxxx>
2011/11/13 Jean-Armel Luce <jaluce06@xxxxxxxxx>:
just for the value : rsync --checksum is the option to use to prevent> Hi Jerry and Kevin,
>
> Thanks for your answers.
>
> Jerry, I tried as you said with the parameter recovery_target_timeline =
> 'latest' and it works.
>
> I tried on a smaller test database (only 15MB) with PG9.1.1 and only 1
> slave.
>
> My switchover procedure was :
>
> Step 1 : stop the old master
> /usr/local/pgsql/bin/pg_ctl stop -m immediate -D
> /usr/local/pgsql91/server1/data
>
> Step 2 : promote slave as master :
> touch /usr/local/pgsql91/server2/data/trigger_file
>
> Step 3 : declare the old master as a standby server
> Step 3.1 : vi /usr/local/pgsql91/server1/data/postgresql.conf
> Add hot_standby = on in the postgresql.conf
>
> Step 3.2 Set recovery.conf for old master server (including
> recovery_target_timeline = 'latest')
> cp /usr/local/pgsql91/server1/data/recovery.bkp
> /usr/local/pgsql91/server1/data/recovery.conf
>
> Step 4 : start old master
> /usr/local/pgsql/bin/pg_ctl start -D /usr/local/pgsql91/server1/data &
>
>
> The old master is now a hot_standby of the new master. Replication works
> without rsyncing all data from new master to new slave.
>
>
> Tomorrow, I shall try with PG9.0.3, 3 slaves and a primary database with 100
> GB.
>
> Thanks.
>
> Jal
copying of identical files (it computes checksum on both side before
sending)
--
Cédric Villemain +33 (0)6 20 30 22 52
http://2ndQuadrant.fr/
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