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
Configuring erasure coding for a Flexible Storage Sharing file system
You can create an erasure-coded layout to tolerate the loss of node or disks based on your configuration.
Currently, Veritas Access supports configuring erasure coding in the following use cases:
An erasure-coded volume with stripe_aligned=no is used for this use case. There are no I/O pattern or file system allocation restrictions with stripe_aligned=no option. The stripe_aligned=no option internally uses the Erasure Coding (EC) log to ensure data consistency. EC support for NFS use case is available only for a cluster file system.
An erasure-coded volume can be optimally tuned for such use cases. To use EC in this case, an erasure-coded volume is created with stripe_aligned=yes option. So, the logging and locking overhead is eliminated and performance is improved. But the object allocation should be aligned to the erasure-coded stripe length to configure EC for LTR use case. EC support in a cluster file system for LTR use case is available in this release. EC support in a scale-out file system for LTR use is a technical preview feature in this release.
Veritas recommends some tuning recommendations for an erasure-coded file system. Configuring erasure coding for a Flexible Storage Sharing (FSS) file system is dependent on the following factors:
The most frequently used I/O size, if any.
The number of faults that the user wants to tolerate.
The underlying storage attached to the cluster nodes (for example, SSD, HDD).
The stripe_width that is used for striping an erasure-coded volume is dependent on:
The most frequently used I/O size, if any
The underlying storage attached to the cluster nodes (for example, SSD, HDD).
For example:
If the underlying storage is SSD and frequent I/Os of some specific size is expected, then Veritas recommends that you should choose stripe_width such that stripe_length is equal to frequent I/O size.
stripe_length = stripe_width * number_of_data_columns stripe_length = frequent_io_size
Thus,
stripe_width = frequent_io_size / number_of_data_columns
If the underlying storage is HDD and frequent I/Os of some specific size is expected, then Veritas recommends that you should choose stripe_width equal to frequent I/O size.
If I/Os of random size are expected, then stripe_width should be equal to the optimal I/O size on the underlying devices.
Note:
Erasure coding is only supported in an FSS environment.