RDF System Management Manual
Table Of Contents
- RDF System Management Manual
- What’s New in This Manual
- About This Manual
- 1 Introducing RDF
- RDF Subsystem Overview
- RDF Processes
- RDF Operations
- Reciprocal and Chain Replication
- Available Types of Replication to Multiple Backup Systems
- Triple Contingency
- Loopback Configuration (Single System)
- Online Product Initialization
- Online Database Synchronization
- Online Dumps
- Subvolume- and File-Level Replication
- Shared Access DDL Operations
- EMS Support
- SMF Support
- RTD Warning Thresholds
- Process-Lockstep Operation
- Support for Network Transactions
- RDF and NonStop SQL/MX
- Zero Lost Transactions (ZLT)
- Monitoring RDF Entities With ASAP
- 2 Preparing the RDF Environment
- 3 Installing and Configuring RDF
- 4 Operating and Monitoring RDF
- 5 Managing RDF
- Recovering From File System Errors
- Handling Disk Space Problems
- Responding to Operational Failures
- Stopping RDF
- Restarting RDF
- Carrying Out a Planned Switchover
- Takeover Operations
- Reading the Backup Database
- Access to Backup Databases in a Consistent State
- RDF and NonStop SQL/MP DDL Operations
- RDF and NonStop SQL/MX Operations
- Backing Up Image Trail Files
- Making Online Dumps With Updaters Running
- Doing FUP RELOAD Operations With Updaters Running
- Exception File Optimization
- Switching Disks on Updater UPDATEVOLUMES
- 6 Maintaining the Databases
- 7 Online Database Synchronization
- 8 Entering RDFCOM Commands
- 9 Entering RDFSCAN Commands
- 10 Triple Contingency
- 11 Subvolume- and File-Level Replication
- 12 Auxiliary Audit Trails
- 13 Network Transactions
- Configuration Changes
- RDF Network Control Files
- Normal RDF Processing Within a Network Environment
- RDF Takeovers Within a Network Environment
- Takeover Phase 1 – Local Undo
- Takeover Phase 2 – File Undo
- Takeover Phase 3 – Network Undo
- Takeover Phase 3 Performance
- Communication Failures During Phase 3 Takeover Processing
- Takeover Delays and Purger Restarts
- Takeover Restartability
- Takeover and File Recovery
- The Effects of Undoing Network Transactions
- Takeover and the RETAINCOUNT Value
- Network Configurations and Shared Access NonStop SQL/MP DDL Operations
- Network Validation and Considerations
- RDF Re-Initialization in a Network Environment
- RDF Networks and ABORT or STOP RDF Operations
- RDF Networks and Stop-Update-to-Time Operations
- Sample Configurations
- RDFCOM STATUS Display
- 14 Process-Lockstep Operation
- Starting a Lockstep Operation
- The DoLockstep Procedure
- The Lockstep Transaction
- RDF Lockstep File
- Multiple Concurrent Lockstep Operations
- The Lockstep Gateway Process
- Disabling Lockstep
- Reenabling Lockstep
- Lockstep Performance Ramifications
- Lockstep and Auxiliary Audit Trails
- Lockstep and Network Transactions
- Lockstep Operation Event Messages
- 15 NonStop SQL/MX and RDF
- Including and Excluding SQL/MX Objects
- Obtaining ANSI Object Names From Updater Event Messages
- Creating NonStop SQL/MX Primary and Backup Databases from Scratch
- Creating a NonStop SQL/MX Backup Database From an Existing Primary Database
- Online Database Synchronization With NonStop SQL/MX Objects
- Offline Synchronization for a Single Partition
- Online Synchronization for a Single Partition
- Correcting Incorrect NonStop SQL/MX Name Mapping
- Consideration for Creating Backup Tables
- Restoring to a Specific Location
- Comparing NonStop SQL/MX Tables
- 16 Zero Lost Transactions (ZLT)
- A RDF Command Summary
- B Additional Reference Information
- C Messages
- D Operational Limits
- E Using ASAP
- Index
Entering RDFCOM Commands
HP NonStop RDF System Management Manual—524388-003
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Command Overview
TAKEOVER
The TAKEOVER command causes the backup database to become transactionally
consistent and available as the database of record.
!
Causes the takeover to be performed immediately, with no attempt to verify that the
primary system is inaccessible.
Be careful. If you include the "!" and the primary system is still accessible,
executing the TAKEOVER command could put your backup database out of
synchronization with the primary database. You should only use the "!" if you are
absolutely certain the primary is down and you want the takeover to proceed
immediately.
Where Issued
Backup system only.
Security Restrictions
You can issue the TAKEOVER command if you are the member of the super-user
group that initialized RDF.
RDF State Requirement
Normally you can issue the TAKEOVER command only if the communication lines
between the backup and primary systems are down, or the monitor process is not
running on the primary system. You can, however, override this requirement by
including the "!" in the command.
If you omit the exclamation point, RDFCOM prompts you to ensure that you really want
to perform a takeover. If you answer yes (Y), RDFCOM attempts to contact the
primary system. If the primary system responds, the TAKEOVER command is aborted
immediately. If the primary system is inaccessible, Expand returns an error (which
could take several minutes to happen). The "!" eliminates both the prompt and the
subsequent delay.
TAKEOVER [!]