[MAPREDUCE-496] If mapred.local.dir is configured on top of dfs.data.dir, hadoop should refuse to start rather than deleting the contents of local.dir

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Labels: newbie
• Assignee: Unassigned
• Reporter: Todd Lipcon
• Created: 06/Dec/08 22:39
• Updated: 21/Jul/14 17:04

Description

I just managed to blow away a DFS by accidentally misconfiguring dfs.data.dir and mapred.local.dir to contain several directories in common. On startup, the task tracker clears out mapred.local.dir, which obviously screws over the datanode.

This should be a reasonably easy check to put in place to make hadoop more idiot proof (or in my case lack-of-sleep proof)