drupalsrv02 runs as a hot spare for drupalsrv01, databases content is replicated 'on-the-fly', filesystem content is mirrored every 15 minutes.

In order to move service to drupalsrv02 all web aliases must be moved to that host, proceed as follows:

1. shutdown apache on drupalsrv01 (if still possible ..) 
2. edit (crontab -e) root cronjob on drupalsrv01 (if still possible ..) 
3. on drupalsrv02 run /data02/bin/move.all.web.redir.sh drupalsrv02
4. edit (crontab -e) root cronjob on drupalsrv02

After DNS update within few minutes sites will be served from drupalsrv02.