1. Install VMware-Tools (I think it should be installed but unlucky still a lots out there do not know how to install on Linux)
2. Create a script /usr/sbin/pre-freeze-script
#!/bin/bash
# Just a log with date, you can remove it
echo $(date) >> /var/log/snapshot.log
# Assume Domino Service is installded and started by user "domino", we drop all connection and flush all database cache
/bin/su - domino -c "cd /local/notesdata/;/opt/ibm/lotus/bin/server -c \"drop all\";/opt/ibm/lotus/bin/server -c \"dbcache flush\""
# Some forks saying we should do a sync before backup, run it with no harm...
/bin/sync
3. chmod 755
/usr/sbin/pre-freeze-script
4. In VMware vSphere, take a snapshot of your Domino Server, uncheck "Snapshot the virtual machine's memory" as it will not run the script is memory is taken and check "Quiesce guest file system".
Check if /var/log/snapshot.log has date recorded and better connect your Domino Console and see if the connection has been dropped when taking snapshot (to prove the script has been run correctly).