InfoScale™ 9.0 Replication Administrator's Guide - AIX
- Section I. Getting started with Volume Replicator
- Introducing Volume Replicator
- Understanding how Volume Replicator works
- How VVR uses kernel buffers for replication
- Replication in a shared disk group environment
- Using SmartTier with VVR
- Understanding the VVR snapshot feature
- About VVR compression
- Planning and configuring replication
- Before you begin configuring
- Choosing the mode of volume replication
- Planning the network
- Sizing the SRL
- Understanding replication settings for a Secondary
- Configuring VVR in a VCS environment
- Using the primary-elect feature to choose the primary site after a site disaster or network disruption
- Requirements for configuring VVR in a VCS environment
- Example setting up VVR in a VCS environment
- Configuring the agents for a bunker replication configuration
- Section II. Setting up and administering VVR
- Setting up replication
- Creating a Replicated Data Set
- Creating a Primary RVG of an RDS
- Adding a Secondary to an RDS
- Changing the replication settings for a Secondary
- Synchronizing the Secondary and starting replication
- Starting replication when the data volumes are zero initialized
- Displaying configuration information
- Displaying RVG and RDS information
- Displaying information about data volumes and volume sets
- Displaying information about Secondaries
- Displaying statistics with the vrstat display commands
- Collecting consolidated statistics of the VVR components
- Displaying network performance data
- Administering Volume Replicator
- Administering data volumes
- Associating a volume to a Replicated Data Set
- Associating a volume set to an RDS
- Associating a Data Change Map to a data volume as a log plex
- Resizing a data volume in a Replicated Data Set
- Administering the SRL
- Incrementally synchronizing the Secondary after SRL overflow
- Administering replication
- Administering the Replicated Data Set
- Administering Storage Checkpoints
- Creating RVG snapshots
- Using the instant snapshot feature
- About instant full snapshots
- Preparing the volumes prior to using the instant snapshot feature
- Creating instant full snapshots
- About instant space-optimized snapshots
- Creating instant space-optimized snapshots
- About instant plex-breakoff snapshots
- Administering snapshots
- Using the traditional snapshot feature
- Using Veritas Volume Manager FastResync
- Verifying the DR readiness of a VVR setup
- Backing up the Secondary
- Administering data volumes
- Using VVR for off-host processing
- Transferring the Primary role
- Migrating the Primary
- About taking over from an original Primary
- Failing back to the original Primary
- Choosing the Primary site after a site disaster or network disruption
- Troubleshooting the primary-elect feature
- Replication using a bunker site
- Introduction to replication using a bunker site
- Setting up replication using a bunker site
- Using a bunker for disaster recovery
- Replication using a bunker site in a VCS environment
- Configuring and administering VVR using System Management Interface Tool
- Accessing Volume Replicator interface in SMIT
- Setting up a simple Volume Replicator configuration using SMIT
- Displaying configuration information using SMIT
- Administering Volume Replicator using SMIT
- Taking instant snapshot of data volumes of an RVG using SMIT
- Associating a volume to a Replicated Data Set using SMIT
- Transferring the Primary role using SMIT
- Troubleshooting VVR
- Recovery from configuration errors
- Errors during an RLINK attach
- Errors during modification of an RVG
- Recovery on the Primary or Secondary
- Recovering from Primary data volume error
- Primary SRL volume error cleanup and restart
- Primary SRL header error cleanup and recovery
- Secondary data volume error cleanup and recovery
- Tuning replication performance
- SRL layout
- Tuning Volume Replicator
- VVR buffer space
- Tuning VVR compression
- VVR buffer space
- Setting up replication
- Section III. Analyzing your environment with Volume Replicator Advisor
- Introducing Volume Replicator Advisor (VRAdvisor)
- Collecting the sample of data
- About collecting the sample of data
- Collecting the sample of data on UNIX
- Collecting the sample of data on Windows
- Analyzing the sample of data
- About analyzing the sample of data
- Analyzing the collected data
- Understanding the results of the analysis
- Viewing the analysis results
- Recalculating the analysis results
- Installing Volume Replicator Advisor (VRAdvisor)
- Section IV. VVR reference
- Appendix A. VVR command reference
- Appendix B. Using the In-band Control Messaging utility vxibc and the IBC programming API
- Using the IBC messaging command-line utility
- Examples - Off-host processing
- In-band Control Messaging API
- Appendix C. Volume Replicator object states
- Appendix D. Alternate methods for synchronizing the Secondary
- Using the full synchronization feature
- Using block-level backup and Storage Checkpoint
- Using difference-based synchronization
- Examples for setting up a simple Volume Replicator configuration
- Appendix E. Migrating VVR from IPv4 to IPv6
- Migrating VVR to support IPv6 or dual stack
- About migrating to IPv6 when VCS global clustering and VVR agents are not configured
- About migrating to IPv6 when VCS global clustering and VVR agents are configured
- About migrating to IPv6 when VCS global clustering and VVR agents are configured in the presence of a bunker
- Migrating to IPv6 when VCS global clustering and VVR agents are configured in the presence of a bunker
- Appendix F. Sample main.cf files
Example - Migrating the Primary role in a setup with multiple Secondaries
We recommend that you create RLINKs between hosts london and tokyo when setting up the RDS.
Note:
Create SRLs of the same size on the Primary and Secondary hosts.
Before migration, the configuration of the RDS looks like this:
On Primary | On Secondary | On Secondary | |
---|---|---|---|
Host Name displayed by the vradmin printrvg command | seattle | london | tokyo |
RVG | hr_rvg | hr_rvg | hr_rvg |
RLINKs | rlk_london_hr_rvg (active) | rlk_seattle_hr_rvg (active) | rlk_seattle_hr_rvg (active) |
rlk_tokyo_hr_rvg (active) | rlk_tokyo_hr_rvg | rlk_london_hr_rvg |
To migrate the Primary RVG hr_rvg to host london:
- Stop the applications that use the Primary data volumes. For example, if the application is a file system, unmount it.
- Verify that the Primary RLINKs are up-to-date by using the vxrlink status command. On the Primary seattle, issue the following commands:
# vxrlink -g hrdg status rlk_london_hr_rvg # vxrlink -g hrdg status rlk_tokyo_hr_rvg
The vradmin migrate command fails if the Primary RLINKs are not up-to-date or not in the CONNECT state. It also fails if the data volumes are active.
- Migrate the Primary RVG hr_rvg by typing the following command from any host in the RDS:
# vradmin -g hrdg migrate hr_rvg london
- If you had created RLINKs between the Secondary london and the additional Secondary tokyo, host tokyo is automatically added to the new configuration.
Otherwise, you must manually add tokyo as a Secondary to the new Primary london. To do this, create RLINKs between london and tokyo and associate them to the respective RVGs using the following commands.
On host london:
# vxmake -g hrdg rlink rlk_tokyo_hr_rvg local_host=london \ remote_host=tokyo remote_rlink=rlk_london_hr_rvg \ remote_dg=hrdg # vxrlink -g hrdg assoc hr_rvg rlk_tokyo_hr_rvg
On host tokyo:
# vxmake -g hrdg rlink rlk_london_hr_rvg local_host=tokyo \ remote_host=london remote_rlink=rlk_tokyo_hr_rvg \ remote_dg=hrdg # vxrlink -g hrdg assoc hr_rvg rlk_london_hr_rvg
By default, the vxmake rlink command creates the RLINK with the protocol set to TCP/IP. If necessary, you can change the protocol to UDP/IP.
- Start replication to tokyo using the following command:
# vradmin -g hrdg -f startrep hr_rvg tokyo
Note:
Ensure that the above command is run before starting the application on the new Primary london.
- Restart the application.
Because the application was stopped properly before the migration, an application recovery is not required.
By default, the vradmin migrate command enables replication from the new Primary london. To start the application before enabling replication, first, issue the vradmin pauserep command, start the application, and then resume replication.
After migration, the configuration of the RDS looks like this:
On Primary
On Secondary
On Secondary
Host Name
displayed by the command:
vradmin printrvg
london
seattle
tokyo
RVG
hr_rvg
hr_rvg
hr_rvg
RLINKs
rlk_seattle_hr_rvg (active)
rlk_london_hr_rvg (active)
rlk_london_hr_rvg (active)
rlk_tokyo_hr_rvg (active)
rlk_tokyo_hr_rvg
rlk_seattle_hr_rvg