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 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
- 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 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
- Configuring Veritas Access with the NetBackup client
- Section XI. Reference
Tuning the writeback caching
When writeback caching is enabled, any data that is read from the disk is cached, unless the file is explicitly marked for "no caching" or if the cache is full. For writes, certain writes cause the data to be cached. You can load a file to speed up the application. Pinning a file in the cache ensures that the data does not get evicted. If some data is already cached, and that portion of the disk is overwritten, then SmartIO also writes the new data to the cache device to ensure that the cached data remains up to date.
You can use the following tunable parameters to adjust the size of the cache and how long data is held in the cache.
When writeback is enabled, you can configure a maximum for the space used for dirty data per node. By default, there is no maximum. If you configure a maximum, you must allow at least 512 MB for each file system or cluster file system. For a cluster file system, the space required for data reflection is not included in the maximum.
To set the writeback size
- Run the following command to configure the maximum. For a cluster file system, run the command on each node of the cluster to make the setting cluster wide.
SmartIO> cache wb_size nodename cachename cache_size
Where:
nodename specifies the cluster node.
cachename specifies the name of the cache.
cache_size specifies the size of the cache.
- For the changed value to take affect, run the following command.
SMARTIO> fs enable target1
- The writeback size is shown as Writeback Cache Use Limit, when you display the cache statistics. To display the cache statistics:
SMARTIO> cache stat