The default value is
1. This default value creates one copy of each block, in addition
to the original block. When the INNAMEONLY option is specified, the
default is 2. Replicated blocks are used to provide fault tolerance
for HDFS. If a machine in the cluster becomes unavailable, then the
blocks needed for the SASHDAT file can be retrieved from replications
on other machines.
You can specify COPIES=0
to avoid creating redundant blocks for the SASHDAT file. This option
can be useful to preserve storage space when you have redundancy for
the source data.