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 Veritas Access episodic replication works
Veritas Access episodic replication is an incremental episodic replication service that runs on top of the Cluster File System that is used by Veritas Access which is, in turn, based on the Veritas File System (VxFS). Veritas Access episodic replication uses two file system specific features: File Change Log (FCL) and Storage Checkpoint services, to retrieve file changes between replication periods.
For a given period, the FCL records every change made to the file system. By scanning the FCL, Veritas Access episodic replication quickly identifies the file(s) that have changed and generates the modified file list. This avoids the expensive file system scanning that is normally associated with file-based replication, and which typically results in sub-optimal performance.
Next, Veritas Access episodic replication uses VxFS Storage Checkpoint's metadata comparison feature to retrieve the modified extent list of each changed file. It does not need to access the file data.
The Veritas Access episodic replication transport layer works in conjunction with, and interfaces to the well-known rsync remote file synchronization tool. Using this existing network transportation program makes the network configuration much easier in the enterprise domain: the Secure Socket Shell (SSH) port (22) required by rsync is opened by default on almost all enterprise firewalls. rsync is also a reliable solution for a low bandwidth or unreliable link environment.
Note:
Veritas Access uses the rsync protocol to provide transportation of Veritas Access episodic replication encapsulated files. The use of rsync is not exposed in Veritas Access, and cannot be administered outside of the Veritas Access episodic replication feature set.