Performing File System Operations on HPE Ezmeral Data Fabric Database Tables
The Data Fabric file system stores tables in the same
namespace as files. You can move and delete tables in much the same way as you can with
files. All file system operations remain accessible with the hadoop fs
command.
Volume properties, such as replication factor or rack topology, that apply to the specified
location also apply to tables stored at that location. You can move a table with the Linux
mv
command or the hadoop fs -mv
command.
When you use Direct Access NFS or the hadoop fs -ls
command to access a
Data Fabric cluster, tables and files are listed
together. Because the client's Linux commands are not table-aware, other Linux file
manipulation commands, notably file read and write commands, are not available for HPE Ezmeral Data Fabric Database tables.
This section describes the operations that you can perform on HPE Ezmeral Data Fabric Database tables through a Linux command line when you access the
cluster through NFS or with the hadoop fs
commands.
Setting Permissions
HPE Ezmeral Data Fabric Database tables do not support setting user permissions
through the UNIX chmod
command or the hadoop fs -chmod
analogue. Instead, HPE Ezmeral Data Fabric Database table access is controlled
with Access Control Expressions (ACEs). See Enabling Table and Stream Authorizations with ACEs.
Read and Write
You cannot perform read or write operations on a HPE Ezmeral Data Fabric Database
table from a Linux file system context. For example, you cannot use the
cat
command to view the content of a table or search through a table
with the grep
command. file system returns
an error when an application attempts to read or write to a HPE Ezmeral Data Fabric Database table.
Move
You can move a HPE Ezmeral Data Fabric Database table within a volume with the
mv
command over NFS or with the hadoop fs -mv
command. These moves are subject to the standard permissions restrictions. Moves across
volumes are not currently supported.
Remove
You can remove a table with the rm
command over NFS or with the
hadoop fs -rm
command. These commands remove the table from the
namespace and asynchronously reclaims the disk space. You can remove a directory that
includes both files and tables with the rm -r
or hadoop fs
-rmr
commands.
Copy and Recursive/Directory Copy
Table copying at the file-system level is not supported. See Migrating Between Apache HBase Tables and HPE Ezmeral Data Fabric Database Tables for information on copying tables using the HBase shell.