OpenSolaris Backup Solution with Rsync and ZFS Snapshots

I have recently been forced to learn how to admin an OpenSolaris machine with ZFS filesystems. After doing some reading on ZFS, I realised how using snapshots with an rsync server would make an excellent backup solution.

Using several scripts to control rsync and the snapshots has allowed me to setup a system that has data retention periods applied and only uses the space on disk required to keep the changed files. Cloning a ZFS snapshot from a week ago (or even six months ago) allows you to create a synthetic full backup from the point in time the backup was taken.

Continue reading

pg_standby triggering unexpectedly

I have been having a problem with my redundant PostgreSQL setup over the last couple of weeks. I run two Postgres servers with a WAL Logging Warm Standby system using pg_standby from 8.3. When the master server is under heavy load and generating a lot of WAL traffic the secondary server has been tripping and going active.

After checking all the logs and putting pg_standby in debug mode there was still no clue as to why this was happening.

Continue reading