Volume Replicator 7.4.1 Administrator's Guide - Windows
- Understanding Volume Replicator
- About Volume Replicator
- Basic Volume Replicator terms
- Building blocks of Volume Replicator
- Understanding replication in the Volume Replicator environment
- Modes of replication
- Understanding data flow in Volume Replicator asynchronous mode
- Managing data during failure and recovery
- Replication concepts
- About using Volume Replicator as a disaster recovery tool
- Understanding how Volume Replicator logs writes to the Replicator Log
- Understanding replication settings for a Secondary
- Measures to protect log overflow and replication latency
- Pausing the replication
- Synchronizing the Secondary
- Understanding Volume Replicator support for FlashSnap
- About Synchronized Snapshots
- Understanding Bunker replication
- Understanding Volume Replicator Support for TCP Multi-Connection
- About Volume Replicator memory monitoring and control support
- About Volume Replicator Graphs
- Setting up replication
- Security considerations for Volume Replicator
- Setting up replication using the Setup Replicated Data Set wizard
- Setting up the Bunker RVG for replication
- Using the VEA Console for Volume Replication Operations
- Monitoring replication
- Interpreting the information in the Volume Replicator views
- Monitoring replication using the VEA console
- Checking replication performance using vxrlink stats
- Administering Volume Replicator
- Adding volumes
- Administering the RVG
- Administering replication
- Managing checkpoints
- Pausing replication using Volume Replicator
- Creating snapshots for the data volumes
- Creating synchronized snapshots using the VSS Snapshot wizard
- Administering Bunker replication
- Performing disaster recovery operation
- Deleting Volume Replicator objects
- Accessing data on Secondary host
- Performing automated system recovery (ASR)
- Alternative methods to synchronize the Secondary faster
- Obtaining statistical information through Volume Replicator Graphs
- Using the command line interface
- Administering the RDS using the vxrds command
- Resizing the data volumes
- Displaying the network statistics for the RLINK
- Administering the RVGs using the vxrvg command
- Displaying information using the vxprint command
- Creating snapshots using the vxsnap command
- Administering replicated volumes using the vxvol command
- Displaying and changing replication ports using the vrport command
- Administering the RVG using the vxedit
- Administering the RVG using the vxassist command
- Tuning Volume Replicator
- Examples: Using the command line
- Example 1: Setting up replication using the command line interface
- Example 3: Using Bunker node for disaster recovery
- Example 4: Using synchronized snapshots to restore data
- Configuring Volume Replicator in a VCS environment
- Components of a VCS cluster
- Illustrating a highly available Volume Replicator setup
- How the agents work
- Configuring the agents
- Working with existing replication service groups
- Configuring Volume Replicator with Hyper-V
- Advanced settings in Volume Replicator
- Troubleshooting Volume Replicator
- Recommendations and checks
- Recovering from problems in a firewall or NAT setup
- Recovering from problems during replication
- Error when configuring the VxSAS Service
- Operation time-out errors
- Problems when configuring Volume Replicator in a VCS environment
- Problems when setting performance counters
- Appendix A. Services and ports
- Appendix B. Using the vxrsync utility
- Appendix C. VR Advisor (VRAdvisor)
Understanding the concept of a buffer space
When a write is replicated, Volume Replicator allocates data buffers for it. These data buffers are allocated some memory. The amount of memory (buffer space) available to Volume Replicator affects its performance, which can affect the write performance to the underlying volumes.
To manage buffer space on the Primary and Secondary according to your requirements, use the following tunables:
MAX_MEMORY - Use the vxtune vol_rvio_maxpool_sz command to set a value for the MAX_MEMORY tunable or to view the value that is currently assigned to it.
BASE_MEMORY - Use the vxtune vol_min_lowmem_sz command to set a value for the BASE_MEMORY tunable or to view the value that is currently assigned to it.
NMCOM_POOL_SIZE - Use the vxtune vol_max_nmpool_sz command to set a value for the NMCOM_POOL_SIZE tunable or to view the value that is currently assigned to it.
READBACK_POOL_SIZE - Use the vxtune vol_max_rdback_sz command to set a value for the READBACK_POOL_SIZE tunable or to view the value that is currently assigned to it.
FORCE_MAX_CONNECTION - Use the force_max_conn command to set a value for the FORCE_MAX_CONN tunable or to view the value that is currently assigned to it.
MAX_TCP_COUNT - Use the max_tcp_conn_count command to set a value for the MAX_TCP_COUNT tunable or to view the value that is currently assigned to it.
NMCOM_MAX_MESSAGES - Use the nmcom_max_msgs command to set a value for the NMCOM_MAX_MESSAGES or to view the value that is currently assigned to it.
MAX_RECEIVE_GAP - Use the max_rcvgap command to set a value for the MAX_RECEIVE_GAP tunable or to view the value that is currently assigned to it.
RLINK_READBACK_LIMIT - Use the rlink_rdbklimit command to set a value for the RLINK_READBACK_LIMIT tunable or to view the value that is currently assigned to it.
NETWORK_PACKET_LOSS_TOLERANCE - Use the rp_incr_decr command to set a value for the NETWORK_PACKET_LOSS_TOLERANCE tunable or to view the value that is currently assigned to it.
TCP_SOURCE_RESTRICT - Use the tcp_src_port_restrict command to set a value for the TCP_SOURCE_RESTRICT tunable or to view the value that is currently assigned to it.
IOPATH_LOGGING - Use the iopath_logging command to set a value for the IOPATH_LOGGING tunable or to view the value that is currently assigned to it.
NAT_SUPPORT - Use the nat_support command to set a value for the NAT_SUPPORT tunable or to view the value that is currently assigned to it.