For a non-disruptive migration between ONTAP clusters, SnapMirror Async replication is the recommended and supported method. It allows for creating a synchronized copy of the data on the destination cluster while the source remains online. A controlled cutover (with minimal downtime) can then be performed. In-place upgrades are for the same hardware, 7MTT is for migrating from very old 7-Mode systems, and NFS export/import is not a standard or efficient migration path for ONTAP-to-ONTAP moves.

ONTAP applies deduplication first, then compression on the remaining unique data. If the unique data blocks (after dedupe) are already in a compressed format (e.g., .zip, .jpg, .mp4 files), the compression engine will find no further patterns to compress, resulting in 0% savings. Encryption does not block compression, the ‘none’ policy would turn off both dedupe and compression, and deduplication does not need to be disabled for compression to work.

While all options are valid performance checks, the scenario specifically highlights 85% aggregate capacity. In ONTAP, high aggregate capacity (typically above 80-85%) can lead to increased fragmentation as WAFL struggles to find large, contiguous free blocks. This forces read operations to seek across more disk locations, directly increasing read latency for sequential workloads. This is a more direct and likely cause given the specific metric provided than general network or QoS checks, though those should be examined later. Adding disks is a solution, but investigation should confirm the root cause first.

For small file operations on CIFS, performance is heavily dependent on metadata lookup speed. ‘Metadata Read Acceleration’ stores frequently accessed directory and file metadata on extremely fast storage (like NVMe in an All-Flash array), dramatically speeding up operations like file opens, directory listings, and attribute reads. A Flash Pool aggregate with SSD caching is also beneficial as it caches both hot data and metadata, reducing latency for repetitive access patterns. FabricPool tiers cold data, which doesn’t help hot small files. More snapshots increase overhead. Fractional reserve relates to LUN space guarantees, not file performance.

The ‘min-cooling-days’ setting is a key policy parameter that defines how long a block of data must remain ‘cold’ (not accessed) before it becomes eligible for tiering to the cloud. If this value is set too high (e.g., 90 days), data will stay on the performance tier much longer, resulting in lower cloud tiering efficiency. Snapshot policy doesn’t directly control tiering. A full bucket would cause errors, not low efficiency. If volume tiering was ‘none’, the efficiency would be 0%, not just ‘surprisingly low’.

SnapMirror relies on a common Snapshot copy on the source that also exists on the destination as a baseline for incremental updates. If this baseline Snapshot is deleted on the source, the next update will fail because it cannot find the common starting point. The ‘snapmirror recover’ command is specifically designed for this scenario. It intelligently finds a newer common Snapshot on both systems and re-establishes the relationship without requiring a full re-initialization, preserving network bandwidth and time.

The ‘vserver admin’ role provides full administrative control within the context of a specific SVM (vserver). When tenant administrators connect to the SVM’s management LIF (instead of the cluster LIF), they are logically isolated within that SVM. They can manage their own volumes, quotas, CIFS, NFS, etc., but have no visibility or access to the cluster-level configuration or other SVMs. The ‘vsadmin’ role has limited permissions. Using the cluster CLI or the full ‘admin’ role would grant excessive privileges.

The correct post-switchover restoration process is: First, run ‘metrocluster heal’ to resynchronize the configuration and data from the now-active site back to the original disaster site. This command handles multiple phases. Once the healing is complete and the original disaster site is ready, you issue the ‘metrocluster giveback’ command to perform a controlled switchback, transferring control to the original preferred site. ‘Switchback’ is not the standard command; ‘giveback’ is. The healing must precede the giveback.

In ONTAP, the authentication methods (like ‘anonymous’, ‘simple’, ‘sasl’) for an LDAP client are dependent on the name service switch configuration. The SVM’s ns-switch for the ‘ldap’ database must be configured and point to one or more LDAP servers. Until this is done, System Manager disables the authentication method options because they have no context. Creating a CIFS server or joining AD relates to Kerberos, not generic LDAP client configuration. The LDAP client does not need to be stopped.

For a non-disruptive migration between ONTAP clusters, SnapMirror Async replication is the recommended and supported method. It allows for creating a synchronized copy of the data on the destination cluster while the source remains online. A controlled cutover (with minimal downtime) can then be performed. In-place upgrades are for the same hardware, 7MTT is for migrating from very old 7-Mode systems, and NFS export/import is not a standard or efficient migration path for ONTAP-to-ONTAP moves.0