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
Zero Lost Transactions (ZLT)
HP NonStop RDF System Management Manual—524388-003
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Recovering the Primary System After an RDF ZLT
Ta ke o ve r
The file marked with the question mark must be fixed. Use the SNOOP
FIXUPEOF command to reset the crashopen flag. Then use SNOOP READAUDIT
to read the final record. Note that you cannot use the MERGE option when
specifying the name of the audit-trail file. Because the TMF product is not started,
attempting to use the MERGE option results in an error. Using the example of the
MAT above, specify the MAT volume and subvolume when SNOOP issues the
following prompt:
Audit trail name or 'MERGE' (MERGE): $AUDIT.ZTMFAT.AA
Compare the MAT position of the two records to determine which disk has the most
audit records.
2. Recover the database on your former primary system. How you do this depends
upon whether local disks or remote mirrors received the most audit records (which
you determined in the preceding step).
If all of the remote mirrors (MAT and all auxiliary audit trails) have more or the
same number of audit records as the local disks (this typically happens if
CommitHold was configured and enabled on the primary system when the outage
occurred), do as follows:
1. Issue SCF STOP $audit-vol on the former primary system (this stops the local
disk).
2. Issue SCF STOP $audit-vol on the ZLT standby system (this stops the remote
mirror on the ZLT standby system).
3. Issue SCF START $audit-vol -M (this starts only the remote mirror).
4. Once the remote mirror is started, issue SCF START $audit-vol (which causes
the revive from -M to -P)
5. Start TMF. When startup is complete, the database on the primary system
contains the same data that the database on the backup system had at the
conclusion of the RDF takeover operation.
If any local disk (the MAT or any auxiliary audit trail) has more audit records than
the corresponding remote mirror (this can only happen if CommitHold was not
configured or was configured but disabled on the primary system when the outage
occurred), do as follows:
1. Issue SCF STOP $audit-vol on the ZLT standby system (this stops the remote
mirror on the ZLT standby system).
2. Connect the remote mirror to the former primary system.
3. Issue SCF START $audit-vol (this causes a revive from -P to -M).