NetBackup™ Snapshot Client Administrator's Guide
- Introduction
- Installation
- Policy configuration
- Selecting the snapshot method
- About using alternate client backup
- Configuring alternate client backup
- Policy configuration tips
- About disabling snapshots
- NAS snapshot configuration
- Dynamic data streaming for D-NAS workloads
- Setting up a NAS-Data-Protection policy
- FlashBackup configuration
- Instant Recovery configuration
- About Instant Recovery
- About sizing the cache for Instant Recovery copy-on-write snapshots
- About storage lifecycle policies for snapshots
- Configuration of software-based snapshot methods
- Support for Cluster Volume Manager Environments (CVM)
- Configuration of snapshot methods for disk arrays
- OS-specific configuration tasks
- About IBM DS6000 and DS8000 arrays
- Configuring NetBackup to access the IBM DS6000 or DS8000 array
- About IBM DS4000 array
- About Hitachi SMS/WMS/AMS, USP/NSC, USP-V/VM
- Hitachi array software requirements
- About HP-XP arrays
- About array troubleshooting
- Notes on Media Server and Third-Party Copy methods
- Backup and restore procedures
- Snapshot management
- Troubleshooting
- Logging directories for UNIX platforms
- Logging folders for Windows platforms
- FlashBackup and status code 13
- Appendix A. Managing nbu_snap (Solaris)
- Appendix B. Overview of snapshot operations
About quiescing the database application
Most database applications are transactionally consistent only at particular points in time. Sometimes, they are consistent only after they have been shut down. Since many database applications must be available constantly, many applications can reach transactional consistency at regular intervals or in response to an external event. This process is called application quiesce, described in this section.
In database application quiesce, an external signal or message is sent to a receptive database. In response, the database finishes the current transaction or group of transactions and tells the snapshot consumer when the transactions are complete. The database then waits for the indication that normal operations can resume. After the database indicates that it has reached a state of transactional consistency, the final steps of creating the snapshot can proceed.
Once the snapshot has been created, another signal is sent to the waiting database to resume normal operations. This procedure is called unquiescing the application.