A Task Menu Option Is Not Displayed
You may notice that the task menus do not always display the same task options. Some tasks are only valid for certain types of objects or at certain times. For example, a Check Consistency task can only be performed on a redundant virtual disk. Similarly, if a disk is already offline, the Offline task option is not displayed.
There may be other reasons why a task cannot be run at a certain time. For example, there may already be a task running on the object that must complete before additional tasks can be run.