Hi,
1) Is it possible to do an in-place migration, while keeping all
data in HDFS safely?
yes. stop the HDFS firstly, then run start-dfs.sh -upgrade
2) If it is yes, is there any doc/guidance to do this?
you just want a HDFS upgrade, so I don't think there are some useful doc.
3)
Hi Jerry,
R
efer to the following links for reference:
http://www.michael-noll.com/blog/2011/08/23/performing-an-hdfs-upgrade-of-an-hadoop-cluster/
http://wiki.apache.org/hadoop/Hadoop_Upgrade
Notes:
1. the hadoop version used in the doc may be different from yours, but they
are good references
