ONTAP 9.14

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Autonomous Ransomware Protection use cases and considerations

Autonomous Ransomwware Protection (ARP) is available for NAS workloads beginning with ONTAP 9.10.1. Before deploying ARP, you should be aware of the recommended uses and supported configurations as well as performance implications.

Supported and unsupported configurations

When deciding to use ARP, it’s important to ensure that your volume’s workload is suited to ARP and that it meets required system configurations.

Suitable workloads

ARP is suited for:

  • Databases on NFS storage

  • Windows or Linux home directories

    Because users could create files with extensions that weren’t detected in the learning period, there a is greater possibility of false positives in this workload.

  • Images

    For example, health care records and Electronic Design Automation (EDA) data

Unsuitable workloads

ARP is not suited for:

  • Workloads with a high frequency of file create or delete (hundreds of thousands of files in few seconds; for example, test/development workloads)

  • ARP’s threat detection depends on its ability recognize an unusual surge in file create, rename, or delete activity. If the application itself is the source of the file activity, it cannot be effectively distinguished from ransomware activity.

  • Workloads where the application or the host encrypts data
    ARP depends on distinguishing incoming data as encrypted or unencrypted. If the application itself is encrypting the data, then the effectiveness of the feature is reduced. However, the feature can still work based on file activity (delete, overwrite, or create, or a create or rename with a new file extension) and file type.

Supported configurations

ARP is available for NFS and SMB volumes in on-premises ONTAP systems beginning with ONTAP 9.10.1.

Support for other configurations and volume types is available in the following ONTAP versions:

ONTAP 9.14.1 ONTAP 9.13.1 ONTAP 9.12.1 ONTAP 9.11.1 ONTAP 9.10.1

Volumes protected with Asynchronous SnapMirror

SVMs protected with Asynchronous SnapMirror

SVMs enabled for data migration

FlexGroup volumes

Multi-admin verification

SnapMirror and ARP interoperability

Beginning with ONTAP 9.12.1, ARP is supported on Asynchronous SnapMirror destination volumes. ARP is not supported with SnapMirror Synchronous.

If a SnapMirror source volume is ARP-enabled, the SnapMirror destination volume automatically acquires the ARP configuration state (learning, enabled, etc), ARP training data, and ARP-created Snapshot of the source volume. No explicit enablement is required.

While the destination volume consists of read-only (RO) Snapshot copies, no ARP processing is done on its data. However, when the SnapMirror destination volume is converted to read-write (RW), ARP is automatically enabled on the RW-converted destination volume. The destination volume does not require any additional learning procedure besides what is already recorded on the source volume.

In ONTAP 9.10.1 and 9.11.1, SnapMirror does not transfer the ARP configuration state, training data, and Snapshot copies from source to destination volumes. Hence when the SnapMirror destination volume is converted to RW, ARP on the destination volume must be explicitly enabled in learning mode after conversion.

ARP with VMDKs on NFS

If you plan to use ARP in a VMDK on NFS configuration, there are limitations to ARP’s protection. ARP offers protection in VDMK on NFS configurations, however it is not recommended for workloads with high-entropy files inside the VM.

Changes outside the VM

ARP can detect file extension changes on an NFS volume outside of the VM if a new extension enters the volume encrypted or a file extension changes. Detectable file extension changes are:

  • .vmx

  • .vmxf

  • .vmdk

  • -flat.vmdk

  • .nvram

  • .vmem

  • .vmsd

  • .vmsn

  • .vswp

  • .vmss

  • .log

  • -\#.log

Changes inside the VM

If the ransomware attack targets the VM and files inside of the VM are altered without making changes outside the VM, ARP detects the threat if the default entropy of the VM is low (for example .txt, .docx, or .mp4 files). Although ARP will create a protective Snapshot in this scenario, it will not generate a threat alert because the file extensions outside of the VM have not been tampered with.

If, by default, the files are high-entropy (for example .gzip or password-protected files), ARP will not detect a change in baseline entropy and thus will not detect the threat.

Unsupported configurations

ARP is not supported in the following system configurations:

  • ONTAP S3 environments

  • SAN environments

ARP does not support the following volume configurations:

  • FlexGroup volumes (in ONTAP 9.10.1 through 9.12.1. Beginning with ONTAP 9.13.1, FlexGroup volumes are supported)

  • FlexCache volumes (ARP is supported on origin FlexVol volumes but not on cache volumes)

  • Offline volumes

  • SAN-only volumes

  • SnapLock volumes

  • SnapMirror Synchronous

  • Asynchronous SnapMirror (Unsupported only in ONTAP 9.10.1 and 9.11.1. Asynchronous SnapMirror is supported beginning with ONTAP 9.12.1. For more information, see SnapMirror and ARP interoperability.)

  • Restricted volumes

  • Root volumes of storage VMs

  • Volumes of stopped storage VMs

ARP performance and frequency considerations

ARP can have a minimal impact on system performance as measured in throughput and peak IOPS. The impact of the ARP feature depends on the specific volume workloads. For common workloads, the following configuration limits are recommended:

Workload characteristics Recommended volume limit per node Performance degradation when per-node volume limit is exceeded *

Read-intensive or the data can be compressed.


4% of maximum IOPS

Write-intensive and the data cannot be compressed.


10% of maximum IOPS

* System performance is not degraded beyond these percentages regardless of the number of volumes added in excess of the recommended limits.

Because ARP analytics run in a prioritized sequence, as the number of protected volumes increases, analytics run on each volume less frequently.

Multi-admin verification with volumes protected with ARP

Beginning with ONTAP 9.13.1, you can enable multi-admin verification (MAV) for additional security with ARP. MAV ensures that at least two or more authenticated administrators are required to turn off ARP, pause ARP, or mark a suspected attack as a false positive on a protected volume. Learn how to enable MAV for ARP-protected volumes.

You need to define administrators for a MAV group and create MAV rules for the security anti-ransomware volume disable, security anti-ransomware volume pause, and security anti-ransomware volume attack clear-suspect ARP commands you want to protect. Each administrator in the MAV group must approve each new rule request and add the MAV rule again within MAV settings.

Beginning with ONTAP 9.14.1, ARP offers alerts for the creation of an ARP Snapshot and for the observation of a new file extension. Alerts for these events are disabled by default. Alerts can be set at the volume or SVM level. You can create MAV rules at the SVM level using security anti-ransomware vserver event-log modify or at the volume level with security anti-ransomware volume event-log modify.

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