question Re: File URI required for dfs.datanode.data.dir ? in Archives of Support Questions (Read Only)

File URI required for dfs.datanode.data.dir ?

hawkins_house_d — Tue, 21 Mar 2017 09:49:39 GMT

Greeings, all.

Can anybody tell me if a File URI is mandatory for each component of the value of the dfs.datanode.data.dir element in the hdfs-site.xml file?

For example, am I required to specify "file:///grid/hadoop/hdfs/dn, file:///grid1/hadoop/hdfs/dn"? Or, could I use "/grid/hadoop/hdfs/dn, /grid1/hadoop/hdfs/dn", instead, and have effectively the same metadata?

I'm using HDP 2.4.3.

Thanks very much!

~ Joseph

Re: File URI required for dfs.datanode.data.dir ?

ssharma — Tue, 21 Mar 2017 10:14:32 GMT

@Joseph Hawkins Can you please tell me the action/operation which you are trying ?

Re: File URI required for dfs.datanode.data.dir ?

namaheshwari — Tue, 21 Mar 2017 12:27:34 GMT

@Joseph Hawkins - You can just have the value as "/grid/hadoop/hdfs/dn,/grid1/hadoop/hdfs/dn" if they are simple directories on the file system. This is the list of directories where the data will be stored. However, if you have Heterogeneous storage (like DISK, SSD, ARCHIVE or RAM_DISK) you would need to append the File URI.

Below is a very good article explaining HDFS Metadata Directories:

https://hortonworks.com/blog/hdfs-metadata-directories-explained/