In addition to standard monitoring on a per-share basis, it is also possible to monitor shadow migration system-wide through Analytics. The shadow migration analytics are available under the "Data Movement" category. There are three basic statistics available:
Shadow Migration Requests - This statistic tracks requests for files or directories that are not cached and known to be local to the filesystem. It does account for both migrated and unmigrated files and directories, and it can be used to track the latency incurred as part of shadow migration, as well as track the progress of background migration. It can be broken down by file, share, project, or latency. It currently encompasses both synchronous and asynchronous (background) migration, so it is not possible to view only latency visible to clients.
Shadow Migration Bytes - This statistic tracks bytes transferred as part of migrating file or directory contents. This does not apply to metadata (extended attributes, ACLs, etc). It gives a rough approximation of the data transferred, but source datasets with a large amount of metadata will show a disproportionally small bandwidth. The complete bandwidth can be observed by looking at network analytics. This statistic can be broken down by local filename, share, or project.
Shadow Migration Operations - This statistic tracks operations that require going to the source filesystem. This can be used to track the latency of requests from the shadow migration source. It can be broken down by file, share, project, or latency.