Manage Azure NetApp Files standard storage with cool access

Using Azure NetApp Files standard storage with cool access, you can configure inactive data to move from Azure NetApp Files Standard service-level storage (the hot tier) to an Azure storage account (the cool tier). In doing so, you reduce the total cost of ownership of your data stored in Azure NetApp Files.

The standard storage with cool access feature allows you to configure a Standard capacity pool with cool access. The Standard storage service level with cool access feature moves cold (infrequently accessed) data from the volume and the volume's snapshots to the Azure storage account to help you reduce the cost of storage. Throughput requirements remain the same for the Standard service level enabled with cool access. However, there can be a difference in data access latency because the data needs to be read from the Azure storage account.

The standard storage with cool access feature provides options for the “coolness period” to optimize the network transfer cost, based on your workload and read/write patterns. This feature is provided at the volume level. See the Set options for coolness period section for details. The standard storage with cool access feature also provides metrics on a per-volume basis. See the Metrics section for details.

Considerations

• No guarantee is provided for any maximum latency for client workload for any of the service tiers.
• This feature is available only at the Standard service level. It's not supported for the Ultra or Premium service level.
• Although cool access is available for the Standard service level, how you're billed for using the feature differs from the Standard service level charges. See the Billing section for details and examples.
• You can convert an existing Standard service-level capacity pool into a cool-access capacity pool to create cool access volumes. However, once the capacity pool is enabled for cool access, you can't convert it back to a non-cool-access capacity pool.
• A cool-access capacity pool can contain both volumes with cool access enabled and volumes with cool access disabled.
• To prevent data retrieval from the cool tier to the hot tier during sequential read operations (for example, antivirus or other file scanning operations), set the cool access retrieval policy to "Default" or "Never." For more information, see Enable cool access on a new volume.
• After the capacity pool is configured with the option to support cool access volumes, the setting can't be disabled at the capacity pool level. However, you can turn on or turn off the cool access setting at the volume level anytime. Turning off the cool access setting at the volume level stops further tiering of data. 
• You can't use large volumes with Standard storage with cool access.
• See Resource limits for Azure NetApp Files for maximum number of volumes supported for cool access per subscription per region.
• Considerations for using cool access with cross-region replication (CRR) and cross-zone replication:
  • If the volume is in a CRR relationship as a source volume, you can enable cool access on it only if the mirror state is Mirrored. Enabling cool access on the source volume automatically enables cool access on the destination volume.
  • If the volume is in a CRR relationship as a destination volume (data protection volume), enabling cool access isn't supported for the volume.
  • The cool access setting is updated automatically on the destination volume to be the same as the source volume. When you update the cool access setting on the source volume, the same setting is applied at the destination volume.
• Considerations for using cool access with Azure NetApp Files backup:
  • When a backup is in progress for a volume, you can’t enable cool access on the volume.
  • If a volume already contains cool-tiered data, you can’t enable backup for the volume.
  • If backup is already enabled on a volume, you can enable cool access only if the baseline backup is complete.
• Considerations for using cool access with snapshot restore:
  • When restoring a snapshot of a cool access enabled volume to a new volume, the new volume inherits the cool access configuration from the parent volume. Once the new volume is created, the cool access settings can be modified.
  • You can't restore from a snapshot of a non-cool-access volume to a cool access volume. Likewise, you can't restore from a snapshot of a cool access volume to a non-cool-access volume.
• Considerations for moving volumes to another capacity pool:
  • If you move a cool access volume to another capacity pool (service level change), that pool must also be enabled for cool access.
  • If you disable cool access and turn off tiering on a cool access volume (that is, the volume no longer uses cool access), you can’t move it to a non-cool-access capacity pool. In a cool access capacity pool, all volumes, whether enabled for cool access or not, can only be moved to another cool access capacity pool.

Register the feature

This feature is currently in preview. You need to register the feature before using it for the first time. After registration, the feature is enabled and works in the background. No UI control is required.

1. Register the feature:

   Register-AzProviderFeature -ProviderNamespace Microsoft.NetApp -FeatureName ANFCoolAccess
   

2. Check the status of the feature registration:

   Note

   The RegistrationState may be in the Registering state for up to 60 minutes before changing toRegistered. Wait until the status is Registered before continuing.

   Get-AzProviderFeature -ProviderNamespace Microsoft.NetApp -FeatureName ANFCoolAccess
   

You can also use Azure CLI commands az feature register and az feature show to register the feature and display the registration status.

Enable cool access

To use the Standard storage with cool access feature, you need to configure the feature at the capacity pool level and the volume level.

Configure the capacity pool for cool access

Before creating or enabling a cool-access volume, you need to configure a Standard service-level capacity pool with cool access. You can do so in one of the following ways:

• Create a new Standard service-level capacity pool with cool access.
• Modify an existing Standard service-level capacity pool to support cool-access volumes.

Enable cool access on a new capacity pool  

1. Set up a capacity pool with the Standard service level.
2. Check the Enable Cool Access checkbox, then select Create.

Enable cool access on an existing capacity pool

You can enable cool access support on an existing Standard service-level capacity pool. This action allows you to add or modify volumes in the pool to use cool access.

1. Right-click a Standard service-level capacity pool for which you want to enable cool access.

2. Select Enable Cool Access:

   

Configure a volume for cool access

Standard storage with cool access can be enabled during the creation of a volume and on existing volumes that are part of a capacity pool that has cool access enabled.

Enable cool access on a new volume

1. Select the Volumes menu from the Capacity Pools menu. Select + Add volume to create a new NFS, SMB, or dual-protocol volume.

2. In the Basics tab of the Create a Volume page, set the following options to enable the volume for cool access:

   • Enable Cool Access
     This option specifies whether the volume supports cool access.

   • Coolness Period This option specifies the period (in days) after which infrequently accessed data blocks (cold data blocks) are moved to the Azure storage account. The default value is 31 days. The supported values are between 2 and 183 days.

   • Cool Access Retrieval Policy

     This option specifies under which conditions data will be moved back to the hot tier. You can set this option to Default, On-Read, or Never.

     The following list describes the data retrieval behavior with the cool access retrieval policy settings:

     • Cool access is enabled:
       • If no value is set for cool access retrieval policy:
         The retrieval policy will be set to Default, and cold data will be retrieved to the hot tier only when performing random reads. Sequential reads will be served directly from the cool tier.
       • If cool access retrieval policy is set to Default:
         Cold data will be retrieved only by performing random reads.
       • If cool access retrieval policy is set to On-Read:
         Cold data will be retrieved by performing both sequential and random reads.
       • If cool access retrieval policy is set to Never:
         Cold data will be served directly from the cool tier and not be retrieved to the hot tier.
     • Cool access is disabled:
       • You can set a cool access retrieval policy if cool access is disabled only if there's existing data on the cool tier.
       • Once you disable the cool access setting on the volume, the cool access retrieval policy remains the same.

   

3. Follow one of the following articles to complete the volume creation:

   • Create an NFS volume
   • Create an SMB volume
   • Create a dual-protocol volume

Enable cool access on an existing volume

In a Standard service-level, cool-access enabled capacity pool, you can enable an existing volume to support cool access.

1. Right-click the volume for which you want to enable the cool access.

2. In the Edit window that appears, set the following options for the volume:

   • Enable Cool Access
     This option specifies whether the volume will support cool access.

   • Coolness Period
     This option specifies the period (in days) after which infrequently accessed data blocks (cold data blocks) are moved to the Azure storage account. The default value is 31 days. The supported values are between 2 and 183 days.

   • Cool Access Retrieval Policy

     This option specifies under which conditions data will be moved back to the hot tier. You can set this option to Default, On-Read, or Never.

     The following list describes the data retrieval behavior with the cool access retrieval policy settings:

     • Cool access is enabled:
       • If no value is set for cool access retrieval policy:
         The retrieval policy will be set to Default, and cold data will be retrieved to the hot tier only when performing random reads. Sequential reads will be served directly from the cool tier.
       • If cool access retrieval policy is set to Default:
         Cold data will be retrieved only by performing random reads.
       • If cool access retrieval policy is set to On-Read:
         Cold data will be retrieved by performing both sequential and random reads.
       • If cool access retrieval policy is set to Never:
         Cold data will be served directly from the cool tier and not be retrieved to the hot tier.
     • Cool access is disabled:
       • You can set a cool access retrieval policy if cool access is disabled only if there's existing data on the cool tier.
       • Once you disable the cool access setting on the volume, the cool access retrieval policy remains the same.

   

Modify cool access configuration for a volume

Based on the client read/write patterns, you can modify the cool access configuration as needed for a volume.

1. Right-click the volume for which you want to modify the coolness configuration.

2. In the Edit window that appears, update the Coolness Period and Cool Access Retrieval Policy fields as needed.

Next steps

• Standard storage with cool access in Azure NetApp Files