Number of recall threads. The maximum number of recall threads to be used when recalling items. This is equivalent to the number of simultaneous recalls.

Block recalls. Specifies the maximum number of items that a user is allowed to recall in the specified time period, thus controlling the rate at which an individual user can recall files. By doing this you also prevent any applications do not honor the file system offline attribute from recalling all files that had been archived from a volume.

The default maximum rate is 20 recalls in 10 seconds. This recall limit applies to all users except, by default, members of the local Administrators group. If the recall limit is exceeded, the application receives an Access Denied status. Just how this is displayed to the user depends on each individual application.

Ignore recall limits for local administrators. Controls whether the recall limits apply to members of the local Administrators group on the server that is running the Placeholder Service.