...
Database changes likely occur every second in an MES environment. It is in this area where there is a risk of data loss and RPO tolerance consideration is the most important. Snapshots aren't really an effective means of dealing with recovery from outages which involve rapidly changing transactional data unless they are constantly being taken at short intervals. This is often not practical due to the potential negative impact on the production server of additional load and storage limitations at sites to manage and store all the snapshots.
This traditional backup-and-restore scenario is more suited for databases with lots of real-time transactional data. This can be accomplished by the effective use and planning of Full, Differential, and Transaction Log Backups. One of the main considerations in the strategic deployment of these strategies is the RTO (Recovery Time Objective). A strategy utilizing only a Full Backup and Transaction logs will have a longer RTO than a strategy utilizing a Full Backup followed by Differential backups and transaction logs.
Example of Disaster Recovery Plan
| Anchor | ||||
|---|---|---|---|---|
|
A full copy of the VMWare server.
Servers | Schedule | Retention |
Application | Once every two weeks | One month |
Visualization | Once every two weeks | One month |
Process Historian | Once every two weeks | One month |
SQL Server | Once every two weeks | One month |
OPC | Once a month | One month |
Snapshots
Servers | Schedule | Retention |
Application | Every day | 2 days |
Visualization | Every day | 2 days |
Process Historian | Every day | 2 days |
SQL Server | Every day | 2 days |
OPC | Every day | 2 days |
...