Hello Adrian,
I tried to use -U without "su"- launched directly by root: same behaviour.
Finally I reverted my script to use standard backup (pg_start_backup; rsync; pg_stop_backup)- this works- the only downside is possible collisions with on-line backup/synchronizaiton of other two nodes on master node...
Back to the pg_basebackup issue: it is clear to me that this is an issue of environment which launched pg_basebackup.
Possibly either some privileges or some kernel parameters/limits. Who knows?
Summary: clusterlab's crm_mon launched a shell script starting pg_basebackup which fails to do some its work (pg_basebackup: could not wait for child process: No child processes)- probably due to some failing system call.
How can I report to clusterlabs: What system call fails in pg_basebackup?
Best Regards, Andrej
2016-04-17 1:09 GMT+02:00 Adrian Klaver <adrian.klaver@xxxxxxxxxxx>:
Is the su - even necessary?
pg_basebackup is a Postgres client program you can specify the user you want it to connect to using -U.
Or do you need the script to run as postgres in order to get permissions on wherever you are creating the backup directory?
have to find out why pg_basebackup cannot fork when launched from crm_mon.
I assume crm_mon is this:
http://linux.die.net/man/8/crm_mon
from Pacemaker.
I do not use Pacemaker, but I am pretty sure that running what is a monitoring program in daemon mode and then shelling out to another program is not workable. The docs seem to bear this out:
http://clusterlabs.org/wiki/PgSQL_Replicated_Cluster#Installation
https://github.com/smbambling/pgsql_ha_cluster/wiki/Building-A-Highly-Available-Multi-Node-PostgreSQL-Cluster
