Nutanix Files is a file storage service that supports SMB and NFS protocols. Access Based Enumeration (ABE) is a Windows feature that filters the list of available files and folders on the file server to include only those that the requesting user can access. Nutanix Files also supports replication to a DR site using Async DR.

iscsiadm is a command-line tool that allows you to manage iSCSI connections and devices. The error message shown in the exhibit indicates that there is a problem with connecting to the iSCSI target at x.x.x.250.
https://stackoverflow.com/questions/29954195/error-message-from-iscsiadm-while-trying-to-connect-to-a-iscsi-drive Nutanix volume groups are collections of vDisks that can be exposed to virtual machines or physical hosts using iSCSI protocol. Nutanix volume groups have a whitelist feature that allows you to specify which clients can access them.
https://portal.nutanix.com/page/documents/solutions/details?targetId=BP-2049-Nutanix-Volumes:BP-2049-Nutanix-Volumes
1. The administrator has a mistake when inputting the data services IP. This could cause the iscsiadm command to fail to discover or login to the iSCSI target at x.x.x.250. The administrator should verify that they have entered the correct data services IP for the Nutanix volume group.
2. The client's IQN is no longer in the whitelist of the affected VG. This could cause the iSCSI target to reject or ignore the connection request from the client. The administrator should check that they have added or updated the client's IQN in the whitelist of the Nutanix volume group.

According to Nutanix Support & Insights1, Nutanix Volumes is a feature that provides block storage for both VMs and physical hosts using iSCSI protocol. A volume group (VG) is a collection of one or more disks in a Nutanix storage container.
According to Scale-Out Cloud Block Storage Built For AOS | Nutanix2, Flash Mode is an option that allows you to pin a VG to SSD tier for optimal performance. This can help improve the performance of a database server storage that is experiencing persistent slow queries.
https://portal.nutanix.com/page/documents/solutions/details?targetId=BP-2049-Nutanix-Volumes:BP-2049-Nutanix-Volumes

The Objects Storage Network (internal) is a virtual network that connects all CVMs in a cluster that hosts an object store. The Objects Storage Network (External) is a virtual network that connects external clients to an object store. The Objects Public Network (Internal) and (External) are not required for deploying Objects.
https://hyperhci.com/2019/09/18/nutanix-objects-storage-service/