In our production system, we use dataguard with oracle 9i on an Solaris 8, old but very stable ( damned windows… ) The solaris 8 with the oracle db has, at the time of writing this article, an uptime of 1488 days. Really nice technologie…
We have at work some pc, and so I tried to do a config with dataguard but with Oracle 10g2 R2 on a linux Debian system. At the beginning, I had only one pc, with only 512 ram, so I tried to find a way to do that, and think of virtualization, so I tried Xen as it has open source.
So, this working dataguard configuration works on 2 xen VM, on only 1 host. At this time, I'm still unable to install Oracle 10g2 on a Xen host, so I installed it first on a real host running Debian and then did a backup of the partition, and use this partition with Xen.
The two Xen VM has +/- 300 Mo of ram, not a lot, but enough to play a bit with dataguard.
If you want to see in which mode are operating your current instance, primary or standby role. You have to write this query as sysdba in sqlplus :
SQL> select database_role from v$database