V9 no longer requires Maintenance Mode as all operations carried out can work concurrently.
From V7.6 and onwards, Maintenance Mode was introduced as certain jobs will require running operations to finish and hence stop accepting any other operations. This is due to the fact that these operations need exclusive access to the backup files and can not run concurrently.
The following operations will require VM Backup to enter Maintenance Mode:
- Backup Health Monitor (can be aborted)
- Free Space Wizard
- RDF Optimization Tool
- Retention on Offsite Jobs (does not affect primary locations)
When the Backup Health Monitor (BHM) is running VM Backup will be put in Maintenance Mode. You will get a warning message with the option to gracefully abort it. Other operations such as Scheduled Backups, Manual Backup/Restore operations will automatically abort BHM Maintenance Mode.
It's important to note that the RDF Optimization Tool, Free Space Wizard and Offsite Retention jobs cannot be aborted however.