Incase you want to delete a particular bucket and check how long it takes to download. Use the below.
curl -ku admin:changeme https://XX.XX.XX.XX:8089/services/admin/cacheman/$$bucketid$$/evict -X POST
To get the bucket id(| dbinspect index=indexname). This query result will shows the original path of the data present in splunk. Check the before and after evicting the buckets. Once it is evicted, run search which includes the search results available in the bucket. The buckets will be downloaded in the original path. Index=indexname component=cachemanager action=download bucketid shows it is downloaded.
curl -ku admin:changeme "https://localhost:8089/services/admin/cacheman/_evict" -d path=/path_to_cache/ -d mb=99999999999
you didn't ask for it, but the reverse is:
curl -ku admin:changeme "https://localhost:8089/services/admin/cacheman/_localize" -X POST NOTE - triggering this endpoint will prevent normal evictions from occurring on the indexer afterwards until it restarts - thanks @tonguyen