Veritas Access 7.3 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
- About Flexible Storage Sharing
- Configuring data integrity with I/O fencing
- Configuring ISCSI
- Configuring storage
- Section IV. Managing Veritas Access file access services
- Configuring your 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 Veritas Access to work with Oracle Direct NFS
- Configuring an FTP server
- Configuring your NFS server
- Section V. Managing the Veritas Access Object Store server
- Section VI. Monitoring and troubleshooting
- Section VII. 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 VIII. Configuring cloud storage
- Configuring the cloud gateway
- Configuring cloud as a tier
- About policies for scale-out file systems
- Section IX. 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
- Section X. Managing Veritas Access storage services
- Deduplicating data
- Compressing files
- About compressing files
- Compression tasks
- Configuring SmartTier
- Configuring SmartIO
- Configuring replication
- Replication job failover and failback
- Using snapshots
- Using instant rollbacks
- Configuring Veritas Access with the NetBackup client
- Section XI. Reference
Best practices for using the Veritas Access deduplication feature
The following are best practices when using the Veritas Access deduplication feature:
Deduplication is most effective when the file system block size and the deduplication block size are the same for file systems with block sizes of 4K and above. This also allows the deduplication process to estimate space savings more accurately.
The smaller the file system block size and the deduplication block size, the higher is the time required for performing deduplication. Smaller block sizes such as 1 KB and 2 KB, increase the number of data fingerprints that the deduplication database has to store.
Though the file system block size is data-dependent, the recommended block size for optimal deduplication is 4 KB for file systems less than 1 TB. For file systems 1 TB and above, it is 8 KB.
For VMware NFS datastores that store Virtual Machine Disk Format (VMDK) images, a 4 KB block size is optimal.
Compressed media files for images, music, and video, like JPEG, mp3, .MOV, and databases do not deduplicate or compress effectively.
Home directory file systems are good candidates for deduplication.
Deduplication is a CPU and I/O intensive process. It is a best practice to schedule deduplication when the load on your file systems is expected to be low.
Evaluation of changes in the file system is done by the file system's File Change Log (FCL). Setting the frequency on a too infrequent basis may cause the FCL to rollover, thereby missing changes and deduplication opportunities to the file system.
After enabling deduplication on file systems with existing data, the first deduplication run does a full deduplication. This can be time-consuming, and may take 12 to 15 hours per TB, so plan accordingly.
The deduplication database takes up 1% to 7% of logical file system data. In addition, during deduplication processing, an additional but temporary storage space is required. Though 15% free space is enforced, it is recommended to have 30% free space when the deduplication block size is less than 4096 (4 KB).
If you plan to use the deduplication scheduler, you must have a Network Time Protocol (NTP) server enabled and configured.