Veritas Access Administrator's Guide
- Section I. Introducing Veritas Access
- Section II. Configuring Veritas Access
- Adding users or roles
- Configuring the network
- Configuring authentication services
- Section III. Managing Veritas Access storage
- Configuring storage
- Configuring data integrity with I/O fencing
- Configuring ISCSI
- Veritas Access as an iSCSI target
- Configuring storage
- Section IV. Managing Veritas Access file access services
- Configuring the NFS server
- Setting up Kerberos authentication for NFS clients
- Using Veritas Access as a CIFS server
- About Active Directory (AD)
- About configuring CIFS for Active Directory (AD) domain mode
- About setting trusted domains
- About managing home directories
- About CIFS clustering modes
- About migrating CIFS shares and home directories
- About managing local users and groups
- Configuring an FTP server
- Using Veritas Access as an Object Store server
- Configuring the NFS server
- Section V. Monitoring and troubleshooting
- Section VI. Provisioning and managing Veritas Access file systems
- Creating and maintaining file systems
- Considerations for creating a file system
- Modifying a file system
- Managing a file system
- Creating and maintaining file systems
- Section VII. Configuring cloud storage
- Section VIII. Provisioning and managing Veritas Access shares
- Creating shares for applications
- Creating and maintaining NFS shares
- Creating and maintaining CIFS shares
- Using Veritas Access with OpenStack
- Integrating Veritas Access with Data Insight
- Section IX. Managing Veritas Access storage services
- Compressing files
- About compressing files
- Compression tasks
- Configuring SmartTier
- Configuring SmartIO
- Configuring episodic replication
- Episodic replication job failover and failback
- Configuring continuous replication
- How Veritas Access continuous replication works
- Continuous replication failover and failback
- Using snapshots
- Using instant rollbacks
- Compressing files
- Section X. Reference
How data flows in continuous replication synchronous mode
In synchronous mode of continuous replication, CVR processes an incoming write by performing the following steps.
CVR receives a write on the primary host.
CVR writes it to the primary SRL.
CVR sends the write to the secondary host and waits for the synchronous network acknowledgments from the secondary hosts. At the same time, CVR writes to the data volumes on the primary host.
On the secondary host, CVR receives the write, processes it, and sends a network acknowledgment to the primary host.
CVR sends writes to the data volumes on the secondary host. When the primary host receives a network acknowledgment from the secondary host, CVR acknowledges to the application that the write is complete.
Note:
The secondary RVG sends the network acknowledgment as soon as the write is received in the CVR kernel memory. This removes the time required to write to the secondary data volumes from the application latency. On the primary host, CVR does not wait for data to be written to the secondary data volumes. This improves application performance. However, CVR tracks all such acknowledged writes that have not been written to the data volumes. CVR can replay these tracked writes if the secondary host crashes before writing to the data volumes on the secondary host or if the primary host crashes before it receives the data acknowledgment.
When the write is written to the data volumes on the secondary host, CVR on the secondary host sends a data acknowledgment to the primary host. CVR marks the write as complete in the SRL when the primary receives the data acknowledgment from all the secondary hosts.