DSEFS command line tool

The DSEFS functionality supports operations including uploading, downloading, moving, and deleting files, creating directories, and verifying the DSEFS status.

DSEFS commands are available only in the logical datacenter. DSEFS works with secured and unsecured clusters, see DSEFS authentication.

You can interact with the DSEFS file system in several modes: interactive command line shell, as part of dse commands, or with a REST API.

Interactive DSEFS command line shell

To use the interactive command line shell:

Command line actions
Action	Command line
Launch DSEFS shell	`$ dse fs dsefs / >` The DSEFS prompt shows the current working directory on DSEFS. The current local working directory that you launch DSEFS from is the default directory that is used for searching local files.
Launch DSEFS shell with precedence given to the specified hosts	`$ dse fs --prefer-contact-points -h 10.0.0.2,10.0.0.5` The `--prefer-contact-points` is used in conjunction with the `-h` option to give precedence to the specified hosts, regardless of proximity, when issuing DSEFS commands. As long as the specified hosts are available, DSEFS does not switch to other DSEFS nodes in the cluster. Without the `--prefer-contact-points` option, DSEFS switches to the closest available DSEFS node automatically, even if the `-h` option is used to specify contact points.
View entire DSEFS command list	`$ dsefs / > help`
View help for any DSEFS command	`$ dsefs / > help dsefs_command`
Add a comment to a DSEFS shell command	Use the character. Everything after the character is ignored. `$ dsefs / > get archive.tgz local_archive.tgz #retrieve the archive`
Exit DSEFS shell	Press Ctrl+D or type exit

Configuring DSEFS shell logging

The default location of the DSEFS shell log file .dsefs-shell.log is the user home directory. The default log level is INFO. To configure DSEFS shell logging, edit the installation_location/resources/dse/conf/logback-dsefs-shell.xml file.

Using with the dse command line

Precede the DSEFS command with dse:

$ dse [dse_auth_credentials] fs dsefs_command  [options]

For example, to list the file system status and disk space usage in human-readable format:

$ dse -u user1 -p mypassword fs "df -h"

Optional command arguments are enclosed in square brackets. For example, [dse_auth_credentials] and [-R]

Variable values are italicized. For example, directory and [subcommand].

Working with the local file system in the DSEFS shell

You can refer to files in the local file system by prefixing paths with file:. For example, the following command lists files in the system root directory:

dsefs dsefs://127.0.0.1:5598/ > ls file:/

bin   cdrom  dev  home  lib32  lost+found  mnt  proc  run   srv  tmp  var         initrd.img.old  vmlinuz.old
boot  data   etc  lib   lib64  media       opt  root  sbin  sys  usr  initrd.img  vmlinuz

If you need to perform many subsequent operations on the local file system, first change the current working directory to file: or any local file system path:

dsefs dsefs://127.0.0.1:5598/ > cd file:
dsefs file:/home/user1/path/to/local/files > ls
conf  src  target  build.sbt
dsefs file:/home/user1/path/to/local/files > cd ..
dsefs file:/home/user1/path/to/local >

DSEFS shell remembers the last working directory of each file system separately. To go back to the previous DSEFS directory, enter:

dsefs file:/home/user1/path/to/local/files > cd dsefs:
dsefs dsefs://127.0.0.1:5598/ >

To go back again to the previous local directory:

dsefs dsefs://127.0.0.1:5598/ > cd file:
dsefs file:/home/user1/path/to/local/files >

To refer to a path relative to the last working directory of the file system, prefix a relative path with either dsefs: or file:. The following session creates the directory new_directory in the directory /home/user1:

dsefs dsefs://127.0.0.1:5598/ > cd file:/home/user1
dsefs file:/home/user1 > cd dsefs:
dsefs dsefs://127.0.0.1:5598/ > mkdir file:new_directory
dsefs dsefs://127.0.0.1:5598/ > realpath file:new_directory
file:/home/user1/new_directory
dsefs dsefs://127.0.0.1:5598/ > stat file:new_directory
DIRECTORY file:/home/user1/new_directory:
Owner           user1
Group           user1
Permission      rwxr-xr-x
Created         2017-01-15 13:10:06+0200
Modified        2017-01-15 13:10:06+0200
Accessed        2017-01-15 13:10:06+0200
Size            4096

To copy a file between two different file systems, you can also use the cp command with explicit file system prefixes in the paths:

dsefs file:/home/user1/test > cp dsefs:archive.tgz another-archive-copy.tgz
dsefs file:/home/user1/test > ls
another-archive-copy.tgz archive-copy.tgz  archive.tgz

Authentication

For $ dse dse_auth_credentials you can provide user credentials in several ways, see Connecting to authentication enabled clusters. For authentication with DSEFS, see DSEFS authentication.

Executing multiple commands

DSEFS can execute multiple commands on one line. Use quotes around the commands and arguments. Each command is executed separately by DSEFS.

$ dse fs 'cat file1 file2 file3 file4' 'ls dir1'

DSEFS command options

The following DSEFS commands and arguments are supported:

Supported DSEFS commands and arguments
DSEFS command	Description and command arguments
`append source destination`	Append a local file to a remote file. `source` is the path to the local file to read data from. `destination` is the path to the remote file to append the file to.
`cat file_or_files`	Concatenate files and print on the standard output. `file_or_files` is the file or files in DSEFS to print to standard output. Separate files with a space.
`cd directory`	Change the remote working directory in DSEFS. `directory` is the remote directory to change to. `..` is the parent directory. The DSEFS prompt identifies the current working directory in DSEFS: `dsefs / >` is the default directory `dsefs /dir2 >` is the current working directory `dir2`
`chgrp [options] group path`	Change file or directory group ownership. `-r, -R` recursively changes the file and directory group ownership. `-v` explains in more detail what is being done. `group` the new group name. `path` the file or directory whose group is changed.
`chmod [options] octal permission mode path`	Change the permissions of a file or directory. `-r, -R` recursively changes the file and directory permissions. `-v` explains in more detail what is being done. `octal permission mode` octal representation of permission mode for owner, group, and others. `path` the file or directory whose permissions are changed
`chown [options] path`	Change files or directories ownership and/or group ownership. `-r, -R` recursively changes the file and directory ownership. `-v` explains in more detail what is being done. `-u, --user username` the new owner username. `-g, --group group` the new group owner name. `path` the file or directory whose ownership is changed.
`cp [options] source destination`	Copies a file within a file system or between two file systems. If the destination path points to a different file system than DSEFS, the block size and redundancy options are ignored. `-o, --overwrite` overwrite the destination file if it exists. `-b, --block-size value` The preferred block size in bytes. `-n, --redundancy-factor num_nodes` is how many replicas of the file data to create in DSEFS. This redundancy factor is similar to the replication factor in the database keyspaces, but is more granular. Set this value to one number greater than the number of nodes that are allowed to fail before data loss occurs. For example, set this value to 3 to allow 2 nodes to fail. For simple replication, you can use a value that is equivalent to the replication factor. `source` the source file to be copied. `destination` the destination file to be created.
`df` [options]	List the DSEFS file system status and disk space usage. `-h` to list the sizes in human-readable format. Sizes are rounded to three significant places and presented using units: K (for a kilobyte = 1024 bytes), M (for a megabyte = 1024K), G (for a gigabyte = 1024M), T (for a terabyte = 1024G) Without this option sizes are printed in bytes.
`exit`	Exit the DSEFS shell client. You can also type `Ctrl+D` to exit the shell.
`fsck`	Perform a file system consistency check and repair file system errors. Run fsck after running umount, or if you encounter file write errors (for example, timeouts).
`get source destination`	Get a file from the DSEFS remote file system and copy the file to the local file system. `source` is the path to the DSEFS remote file to copy. `destination` is the path to the local file to create.
`ls [options] [file_system_entry_or_entries]`	List the DSEFS file system entries (files or directories) in the current working directory. `-R` to list subdirectories recursively. `-l` to use a long listing format with metadata. `-h` to list the sizes in human-readable format. Sizes are rounded to three significant places and presented using units: K (for a kilobyte = 1024 bytes), M (for a megabyte = 1024K), G (for a gigabyte = 1024M), T (for a terabyte = 1024G) Without this option sizes are printed in bytes. `-1` limits the number of printed columns to one, so one file is printed per line. This allows the output to more easily be parsed by external tools. `file_system_entry_or_entries` is the directory or directories to list the contents of.
`mkdir [options] dir_or_dirs`	Make a new directory or directories. `-p` to make parent directories as needed. `-b bytes` is the preferred block size for files stored in this directory. `-c, --compression-encoder value` the encoder name to use for compression. DSE ships with the `lz4` compression encoder. `-n, --redundancy-factor num_nodes` is how many replicas of the file data to create in DSEFS. This redundancy factor is similar to the replication factor in the database keyspaces, but is more granular. Set this value to one number greater than the number of nodes that are allowed to fail before data loss occurs. For example, set this value to 3 to allow 2 nodes to fail. For simple replication, you can use a value that is equivalent to the replication factor. `-m, --permission-mode value` octal representation of permission mode for owner, group and others. `dir_or_dirs` is the directory or directories to create.
`mv source destination`	Move or rename a file or directory. `source` is the path to the DSEFS file system entry to be moved. The destination path on DSEFS: `destination` is the full destination path, including the name of the file or directory being moved. `destination/` is the full destination path. If the destination ends with a slash (/) the original file or directory name is retained.
`put [options] source destination`	Copy a local file to the DSEFS. `-o, --overwrite` to overwrite the destination file if it exists. `-b, --block-size bytes` is the preferred block size in bytes. `-c, --compression-encoder value` the encoder name to use for compression. DSE ships with the `lz4` compression encoder. `-n, --redundancy-factor num_nodes` is how many replicas of the file data to create in DSEFS. This redundancy factor is similar to the replication factor in the database keyspaces, but is more granular. Set this value to one number greater than the number of nodes that are allowed to fail before data loss occurs. For example, set this value to 3 to allow 2 nodes to fail. For simple replication, you can use a value that is equivalent to the replication factor. `-f, --compression-frame-size value` the preferred frame size in bytes. Frame is a subject of compression. The bigger the frame the bigger the chance for high compression ratio. For most cases the default value of 131072 bytes is sufficient. `-m, --permission-mode value` octal representation of permission mode for owner, group and others. `source` is the path to the local source file. `destination` is the path to the destination file to be created on DSEFS.
`pwd [path]`	Print the working directory of the current file system or specified path. `path` the current working directory of the file system at the root of the path.
`realpath [options] path`	Print the resolved absolute path for a specified file or directory. `-e, --canonicalize-existing` all components of the path must exist. `-m, --canonicalize-missing` no path components need to exist or be a directory. `path` the path to resolve.
`rename path name`	Rename a file or directory in the current location. `path` is the path to the file system entry to be renamed. `name` is the new name of the file system entry.
`rm [-r, -R] path`	Remove files or directories. `-r, -R` specifies to recursively remove the files or directories. `-v` explain what is being done. `path` is the path to the file system entry to be removed.
`rmdir path`	Remove an empty directory or directories. `path` is the path to the directory to be removed.
`stat file_or_dir [-v]`	Display the file system entry status. `file_or_dir` is the file system. `-v` to print verbose detailed information about the file status.
`truncate file`	Truncate a file to 0 bytes. Useful for retaining the metadata for the file. `file` is the file to truncate.
`umount [-f] locations`	Unmount file system storage locations. `-f` to force unmounting, even if the location is unavailable. `locations` is the UUID (Universal Unique Identifier) of UUIDs of the locations to unmount. Get the UUID from the df command. After running umount, run fsck to add missing block replicas taken away by the unmounted location.

Removing a DSEFS node

When removing a node running DSEFS from a DSE cluster, additional steps are needed to ensure proper correctness within the DSEFS data set.

Make sure the replication factor for the cluster is greater than ONE before continuing.

From a node in the same datacenter as the node to be removed, start the DSEFS shell.
```
$ dse fs
```

Show the current DSEFS nodes with the df command.

$ dsefs > df

$ Location                       Status  DC              Rack   Host               Address        Port  Directory            Used         Free    Reserved
144e587c-11b1-4d74-80f7-dc5e0c744aca  up      GraphAnalytics  rack1  node1.example.com  10.200.179.38  5598  /var/lib/dsefs/data     0  29289783296  5368709120
98ca0435-fb36-4344-b5b1-8d776d35c7d6  up      GraphAnalytics  rack1  node2.example.com  10.200.179.39  5598  /var/lib/dsefs/data     0  29302099968  5368709120

Find the node to be removed in the list and note the UUID value for it under the Location column.
If the node is up, unmount it from DSEFS with the command umount UUID.
If the node is not up (for example, after a hardware failure), force unmount it from DSEFS with the command umount -f UUID.
Continue with the normal steps for removing a node.

Examples

Using the DSEFS shell, these commands put the local bluefile to the remote DSEFS greenfile:

dsefs / >  ls -l

dsefs / >  put file:/bluefile greenfile

To view the new file in the DSEFS directory:

dsefs / >  ls -l

Type  Permission  Owner  Group  Length  Modified                  Name
file  rwxrwxrwx   none   none       17  2016-05-11 09:34:26+0000  greenfile

Using the dse command, these commands create the test2 directory and upload the local README.md file to the new DSEFS directory.

$ dse fs "mkdir /test2" &&
dse fs "put README.md /test2/README.md"

To view the new directory listing:

$ dse fs "ls -l /test2"

Type Permission Owner Group Length Modified Name
file rwxrwxrwx none none 3382 2016-03-07 23:20:34+0000 README.md

You can use two or more dse commands in a single command line. This is faster because the JVM is launched and connected/disconnected with DSEFS only once. For example:

$ dse fs "mkdir / test2" "put README.md /test/README.md"