About
Snapshots support storing a copy of data at a particular instant of time. One usage of the snapshot feature may be to roll back a corrupted HDFS instance to a previously known good point in time.
Management
See HDFS - Fs Shell
Allow
See HDFS - DFSAdmin option -allowSnapshot
<snapshotDir>'' : Allow snapshots to be taken on a directory.Disallow
See HDFS - DFSAdmin option -disallowSnapshot
<snapshotDir>'' : Do not allow snapshots to be taken on a directory any more.Diff
HDFS - hdfs command line diff sub-command make a diff of two snapshots of a directory or diff the current directory contents with a snapshot
hdfs snapshotDiff
List
list all snapshottable dirs owned by the current user
hdfs lsSnapshottableDir
Documentation / Reference