Backing Up HDFS Metadata
: Cloudera recommends backing up HDFS metadata before a major
- Stop the cluster. It is particularly important that the NameNode role process is not running so that you can make a consistent backup.
- Go to the HDFS service.
- Click the Configuration tab.
- In the Search field, search for "NameNode Data Directories". This locates the NameNode Data Directories property.
- From the command line on the NameNode
host, back up the directory listed in the NameNode Data Directories property. If
more than one is listed, then you only need to make a backup of one directory,
since each directory is a complete copy. For example, if the data directory is
the following as root:
# cd /mnt/hadoop/hdfs/name # tar -cvf /root/nn_backup_data.tar .
You should see output like this:
./ ./current/ ./current/fsimage ./current/fstime ./current/VERSION ./current/edits ./image/ ./image/fsimageWarning
:If you see a file containing the word lock, the NameNode is probably still running. Repeat the preceding steps, starting by shutting down the CDH services.