Veritas Access provides a scale-out file system that manages a single namespace spanning over both on-premises storage as well as cloud storage, which provides better fault tolerance for large data sets. Unlike a standard file system, a scale-out file system is Active/Passive, which means that the file system can be online on only one node of the cluster at a time. A scale-out file system is always active on the node where its virtual IP address is online. A virtual IP address is associated with a scale-out file system when the file system is created.

Veritas Access supports access to scale-out file systems using NFS-Ganesha and S3. NFS shares that are created on scale-out file systems must be mounted on the NFS clients using the virtual IP address that is associated with the scale-out file system, similarly S3 buckets created on a scale-out file system must be accessed using the same virtual IP address. You can use the CLISH objectaccess> bucket show command to get the virtual IP address. S3 buckets created on a scale-out file system must be accessed using virtual-hosted-style URL (rather than the path-style URL) and the S3 client's DNS must be updated to this virtual IP address for the corresponding virtual-hosted-style URL. If a bucket "bucket1" is created by the S3 client, then its virtual-hosted-style URL would be "bucket1.s3.cluster_name:8143," where the cluster_name is the Veritas Access cluster name and 8143 is the port on which the Veritas Access S3 server is running.

Scale-out file system specifications:

• Twenty percent of a scale-out file system's size is devoted to the metadata container.

• The maximum size of a metadata container is 10 TB.

• The minimum size of a scale-out file system is 10 GB.

• The maximum size of a scale-out file system is 3 PB.

• To create a scale-out file system above 522 TB, you need to provide the file system size in multiples of 128 GB.

• You can grow a scale-out file system up to 522 TB.

• You can shrink the scale-out file system only if its size is less than 522 TB.

A scale-out file system is structured as a layered file system that includes a set of storage containers. The data that is stored in the cloud (Amazon S3, Veritas Access S3, or any S3-compatible cloud storage provider) can be one of the storage containers. One storage container stores the metadata and the other containers store the actual data. This data can be on-premises or can be in the cloud. This modular structure allows the scale-out file system to be more resilient in cases where high capacity or fault tolerance is needed. A scale-out file system accomplishes this without compromising on file system performance.

You can configure Amazon S3, Amazon Glacier, or any S3-compatible cloud storage as a cloud container. Data can be moved between the on-premises container and the cloud container.

With a scale-out file system, you can move file data to the cloud using a tiering mechanism. File metadata including any attributes set on the file resides on-premises. The cloud as a tier feature is best used for moving infrequently accessed data to the cloud.

When Amazon S3 or any S3-compatible cloud storage provider is used as the cloud tier, the data present on S3 can be accessed any time (unlike in Amazon Glacier). An EIO error is returned if you try to write, or truncate the files moved to the S3 tier. If you want to modify the data, move the data to on-premises using tier move or using policies.

Amazon Glacier is an offline cloud tier, which means that data moved to Amazon Glacier cannot be accessed immediately. An EIO error is returned if you try to read, write, or truncate the files moved to the Amazon Glacier tier. If you want to read or modify the data, move the data to on-premises using tier move or using policies. The data is available after some time based on the Amazon Glacier retrieval option you selected.