Thanks Doug, should this be added to the permissions doc or to the
faq? See you in Sonoma.
C
On Jun 11, 2008, at 9:15 PM, Doug Cutting wrote:
Chris Collins wrote:
You are referring to creating a directory in hdfs? Because if I am
user chris and the hdfs only has user foo, then I cant create a
directory because I dont have perms, infact I cant even connect.
Today, users and groups are declared by the client. The namenode
only records and checks against user and group names provided by the
client. So if someone named "foo" writes a file, then that file is
owned by someone named "foo" and anyone named "foo" is the owner of
that file. No "foo" account need exist on the namenode.
The one (important) exception is the "superuser". Whatever user
name starts the namenode is the superuser for that filesystem. And
if "/" is not world writable, a new filesystem will not contain a
home directory (or anywhere else) writable by other users. So, in a
multiuser Hadoop installation, the superuser needs to create home
directories and project directories for other users and set their
protections accordingly before other users can do anything. Perhaps
this is what you've run into?
Doug
