What is the best approach to solve problems like this: Let's say, I have a mail server VM.
1. I am planning to upgrade the mail server, so I take snapshot to have something to revert to in case of disaster.
2. I upgrade the mail server.
3. I leave it working for some time to be sure that there is no problem with the upgrade ... mail server is receiving emails.
4. If everything is working fine, I delete the snapshot.
What if I want to revert to the snapshot? Meanwhile the mail server received some emails, so if I revert to snapshot I loose those emails. Obviously, I cannot loose any emails.
Thank you for any suggestions
