Backing Up HDFS Metadata
: Cloudera recommends backing up HDFS metadata before a major upgrade.
- 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
/mnt/hadoop/hdfs/name, do 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.
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