Veritas Access Appliance Administrator's Guide
- Section I. Introducing Access Appliance
- Section II. Configuring Access Appliance
- Managing users
- Configuring the network
- Configuring authentication services
- Section III. Managing Access Appliance storage
- Configuring storage
- Managing disks
- Configuring ISCSI
- Access Appliance as an iSCSI target
- Configuring storage
- Section IV. Managing Access Appliance file access services
- Configuring the NFS server
- Setting up Kerberos authentication for NFS clients
- Using Access Appliance as a CIFS server
- 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 Access Appliance as an Object Store server
- Configuring the NFS server
- Section V. Managing Access Appliance security
- Section VI. Monitoring and troubleshooting
- Configuring event notifications and audit logs
- About alert management
- Appliance log files
- Configuring event notifications and audit logs
- Section VII. Provisioning and managing Access Appliance file systems
- Creating and maintaining file systems
- Considerations for creating a file system
- About managing application I/O workloads using maximum IOPS settings
- Modifying a file system
- Managing a file system
- Creating and maintaining file systems
- Section VIII. Provisioning and managing Access Appliance shares
- Creating shares for applications
- Creating and maintaining NFS shares
- About the NFS shares
- Creating and maintaining CIFS shares
- About the CIFS shares
- About managing CIFS shares for Enterprise Vault
- Using Access Appliance with OpenStack
- Integrating Access Appliance with Data Insight
- Section IX. Managing Access Appliance storage services
- Compressing files
- About compressing files
- Compression tasks
- Configuring episodic replication
- Episodic replication job failover and failback
- Configuring continuous replication
- How Access Appliance continuous replication works
- Continuous replication failover and failback
- Using snapshots
- Using instant rollbacks
- Compressing files
- Section X. Reference
About the file compression attributes
When you compress a file with the Storage> compress command, compress attaches the following information to the inode:
Compression algorithm
Compression strength, which is a number from 1 to 9
Compression block size
This information is referred to as the file compression attributes. The purpose of the attributes are to collect the parameters used to create the compressed file. The information can then be read by a backup program.
The file compression attributes guarantee that a particular compressed file can only use one type and strength of compression. Recompressing a file using different attributes fails. To change the file compression attributes, you must explicitly uncompress first, and then recompress with the new options, even in the case where all extents are already uncompressed.
The file compression attributes do not indicate if all extents are compressed. Some extents might be incompressible, and other extents or even all extents might be uncompressed due to writes, but the file compression attributes remain. Only an explicit file uncompression can remove the attributes.