Database Reference
In-Depth Information
hadoop dfs -rm /user/MSBigDataSolutions/SampleData1.txt
hadoop dfs -rmr /user/MSBigDataSolutions
NOTE
HDFS is case sensitive.
mydirectory
and
MYDIRECTORY
are treated
by HDFS as two separate directories. Because HDFS automatically
creates directories for you when using some commands (the
put
,
cp
,
and
mv
commands, for example), paying attention to case is important,
as it can be easy to accidentally create directories.
rmr
is useful to clean
up these directories.
Administrative Functions in HDFS
Security in HDFS follows a straightforward model, where files have an
owner and a group. A given file or directory maintains permissions for three
scenarios, which it checks in the following order:
1.
The owner identity
. This is a single-user account, and it tracks the
assigned owner of the file or directory. If the user account accessing the
file matches the owner identity, the user gets the owner's assigned
permissions.
2.
The group identity
. This is a group account, and any user account
with membership in the group gets the group permissions.
3.
All other users
. If the user account does not match the owner
identity, and the user account is not a member of the group, the user
will use these permissions.
