Advanced POS CLI Usage

Based on the UNIX philosophy, POS CLI is designed to be combined with linux commands to provide a number of advanced functionalities. This document describes an advnaced guide to POS CLI with some examples.

Command Auto Completion

Based on Cobra, POS CLI provides command autocompletion for bash and zsh.

Executing the following command will display how to enable the command autocompletion:

/poseidonos/ibofos/bin$ ./poseidonos-cli completion --help

Completion command generates an auto-completion script for bash, zsh, fish, or powershell.

To load completions:

Bash:

  $ source <(poseidonos-cli completion bash)

  # To enable auto completions for every session, execute the following:
  # Linux:
  $ sudo -s
  $ poseidonos-cli completion bash > /etc/bash_completion.d/poseidonos-cli
  $ exit
  $ exec bash (restart session).

  # macOS:
  $ poseidonos-cli completion bash > /usr/local/etc/bash_completion.d/poseidonos-cli

Zsh:

  # If shell completion is not already enabled in your environment,
  # you will need to enable it.  You can execute the following once:

  $ echo "autoload -U compinit; compinit" >> ~/.zshrc

  # To load completions for each session, execute once:
  $ poseidonos-cli completion zsh > "${fpath[1]}/_poseidonos-cli"

  If the command above does not work, try
  $ poseidonos-cli completion zsh > "/usr/local/share/zsh/site-functions/_poseidonos-cli"

  # You will need to start a new shell for this setup to take effect.

Fish:

  $ poseidonos-cli completion fish | source

  # To load completions for each session, execute once:
  $ poseidonos-cli completion fish > ~/.config/fish/completions/poseidonos-cli.fish

PowerShell:

  PS> poseidonos-cli completion powershell | Out-String | Invoke-Expression

  # To load completions for every new session, run:
  PS> poseidonos-cli completion powershell > poseidonos-cli.ps1
  # Add source /yourpath/poseidonos-cli.ps1 file from your PowerShell profile.

Usage:
  poseidonos-cli completion [bash|zsh|fish|powershell]

Follow the instructions according to your shell. After restarting the shell, you will be able to TAB to complete the command automatically.

Combining POS CLI with Linux Commands

You can combine POS CLI with the popular linux commands such as grep and awk. Here, we describe some examples.

Conditional Output Display

The device list command will display all the devices in the system.

/poseidonos/bin$ ./poseidonos-cli device list
| Name       | SerialNumber(SN) | Address      | Class  | MN              | NUMA | Size          |
| ---------- | ---------------- | ------------ | ------ | --------------- | ---- | ------------- |
| unvme-ns-0 | 016              | 0000:4e:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-1 | 017              | 0000:52:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-2 | 018              | 0000:69:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-3 | 019              | 0000:6c:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-4 | 020              | 0000:ce:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |
| unvme-ns-5 | 021              | 0000:d1:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |
| unvme-ns-6 | 022              | 0000:e7:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |
| unvme-ns-7 | 023              | 0000:ea:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |

Using grep, you can display the information of specific devices, arrays, or volumes as in the following examples:

# Displaying the information of "unvme-ns-4" only.
/poseiondonos/bin$ ./poseidonos-cli device list | grep unvme-ns-4
unvme-ns-4     |020                  |0000:ce:00.0   |SYSTEM        |SAMSUNG SSD -Q-                          |1      |3840755982336

# Displaying the information of all the devices except for "unvme-ns-4".
/poseiondonos/bin$ ./poseidonos-cli device list | grep -v unvme-ns-4
| Name       | SerialNumber(SN) | Address      | Class  | MN              | NUMA | Size          |
| ---------- | ---------------- | ------------ | ------ | --------------- | ---- | ------------- |
| unvme-ns-0 | 016              | 0000:4e:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-1 | 017              | 0000:52:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-2 | 018              | 0000:69:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-3 | 019              | 0000:6c:00.0 | SYSTEM | SAMSUNG SSD -Q- | 0    | 3840755982336 |
| unvme-ns-5 | 021              | 0000:d1:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |
| unvme-ns-6 | 022              | 0000:e7:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |
| unvme-ns-7 | 023              | 0000:ea:00.0 | SYSTEM | SAMSUNG SSD -Q- | 1    | 3840755982336 |

Using awk, you can display the conditional information of specific devices, arrays, or volumes as in the following examples:

# Displaying the name, the serial number, and the size of the devices whose serial number is greater than 19.
/poseidonos/bin$ ./poseidonos-cli device list | awk -F "|" '$2 > 19 {print $1 $2 $7 }'
Name           SerialNumber(SN)     Size
unvme-ns-4     020                  3840755982336
unvme-ns-5     021                  3840755982336
unvme-ns-6     022                  3840755982336
unvme-ns-7     023                  3840755982336
  • Note: you need to set the field separator of awk to ‘’. POS CLI uses ‘’ as the default field separator (because there can be some whitespace in the data). You can change the field separator of POS CLI using the –fs option.

Try building your own custom command lines and scripts to fully utilize the potential of POS!

Samsung Electronics © 2022. All rights reserved.