You can specify multiple directories for Namenode data, in which case the image is written to all the directories. You can also an NFS mount, raid or similar approach.
Raghu. Ankur Sethi wrote:
Thank you for the information. I want to take a worse case scenario if the namenode fails. So you are suggesting copying the dfs.name.dir directory. We can take regular backups of this? Shouldn't HDFS be truly fault tolerant in this regard? If you have 500 machines shouldn't it replicate the essential data in case of failure. The google file system maintains replicates server critical information as well. Let's say one did not have the dfs.name.dir backed up, what would happen? Thanks, Ankur
