How can I update the sub tasks when I mark a story as on-hold?

[Kira]

When we mark a story with a status of on-hold, how do I get the subtasks to also be on hold as well? Is there something I can set up in the workflow to do this automatically? 

[Nic Brough -Adaptavist-]

You will need to find some code to do this -  a post function to iterate over the sub-tasks, work out which transition to trigger from whatever state they are currently in (remember there may be cases where you don't want to do this - like if a sub-task is already closed) and then trigger their transitions. 

One of the scripting apps can certainly do this, although you might get close with some of the more simple "change status of related issues" apps.