Permissions issues on tachyon.worker.data.folder (/mnt/ramdisk/tachyonworker)

[timothysc]

Issues #90, and #91 were actually behavioral effects to starting daemons as different system/daemon users, and not having permissions to write to the tachyon.worker.data.folder. Presently it makes sense to have the deamons share a common group and to create subfolders with 775 permissions (vs 755), and allow adminstrators to set the group parameter.

e.g.
user:hdfs (namenode & datanode)
user:yarn (resourcemanager & nodemanager)
user:tachyon|hdfs (master & slave)

shared group would be 'hadoop' or 'hdfs'.

Presently I can verify this all works, by hand.

The issue is that the user 'yarn' fails, trying to write to: /mnt/ramdisk/tachyonworker/users