How SMB metadata caching works
Metadata caching enables file attribute caching on SMB 1.0 clients to provide faster access to file and folder attributes. You can enable or disable attribute caching on a per-share basis. You can also configure the time-to-live for cached entries if metadata caching is enabled. Configuring metadata caching is not necessary if clients are connecting to shares over SMB 2.x or SMB 3.0.
When enabled, the SMB metadata cache stores path and file attribute data for a limited amount of time. This can improve SMB performance for SMB 1.0 clients with common workloads.
For certain tasks, SMB creates a significant amount of traffic that can include multiple identical queries for path and file metadata. You can reduce the number of redundant queries and improve performance for SMB 1.0 clients by using SMB metadata caching to fetch information from the cache instead.
While unlikely, it is possible that the metadata cache might serve stale information to SMB 1.0 clients. If your environment cannot afford this risk, you should not enable this feature.