---
title: "Options for Getting Disk Usage on VAST Data"
slug: "options-for-getting-disk-usage-on-vast-data"
description: "Learn efficient ways to monitor disk usage on VAST Data systems using tools like dua CLI and vastpy for quick, accurate insights."
updated: 2026-11-03T18:16:47Z
published: 2026-11-03T18:16:47Z
canonical: "docs.vastdata.com/options-for-getting-disk-usage-on-vast-data"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vastdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Options for Getting Disk Usage on VAST Data

For this kind of workload (one small operation at a time), a local file system usually outperforms a shared file system over the network. There are a few strategies for gathering capacity information:

1. Use a parallel DU implementation ([https://github.com/Byron/dua-cli](https://github.com/Byron/dua-cli) )
  1. **dua** (-> *Disk Usage Analyzer*) is a tool to easily learn about the disk space usage of a given directory. It's parallel by default and will max out your SSD, providing relevant information as fast as possible.
2. Use block storage on VAST Data. The block protocol has the same latency as NFS, but the client can cache aggressively, with a local file system sitting on a remote block device.
3. Get the information from VAST Data, which knows the data size per directory. This solution is the fastest, and it scales to billions of files.

Here's a guide for how to get capacity information from VMS:

```plaintext
$ pip install vastpy
$ export VMS_USER=admin VMS_PASSWORD=123456 VMS_ADDRESS=vast-file-server-vms-kfs2
$ vastpy-cli get --json capacity path=/bonzo/users/alonho
{
  "details": [
    [
      "/bonzo/users/alonho",
      {
        "data": [
          164714614744,
          44616196110,
          662430925429
        ],
        "parent": "/bonzo/users",
        "percent": 100,
        "average_atime": "2024-04-23 13:17"
      }
    ]
  ],
  "keys": [
    "usable",
    "unique",
    "logical"
  ],
  "time": "2025-03-13 06:42:28",
  "sort_key": "usable",
  "root_data": [
    971276700179058,
    796623499846425,
    2257076215609176
  ],
  "small_folders": []
}
```

usable = physical space consumed unique = how much space you reclaim from deleting this directory (dedup would result in a higher ratio of logical to usable, but also results in less reclamation if the same data exists in other directories).

If you also want file counts, you need a quote:

```plaintext
$ vastpy-cli get quotas fields=path,used_capacity_tb,used_inodes,soft_limit,hard_limit,soft_limit_inodes,hard_limit_inodes
path         |soft_limit    |hard_limit     |soft_limit_inodes |hard_limit_inodes |used_inodes |used_capacity_tb
-------------+--------------+---------------+------------------+------------------+------------+-----------------+
/alon/foo    |5000          |10000          |None              |None              |1           |0.0
/            |None          |None           |None              |None              |1           |0.0
/            |None          |None           |None              |None              |1           |0.0
/alontest    |100000000000  |120000000000   |10000             |20000             |3           |0.041
/bla_roy     |None          |None           |None              |None              |1           |0.0
/checkpoints |90000000000   |100000000000   |None              |None              |1           |0.0
/CS-HomeDirs |9000000000000 |10000000000000 |None              |None              |496453      |0.251
/cs_vm_store |None          |2000000000000  |None              |None              |1088        |1.927
/datasets    |None          |10000          |None              |None              |1           |0.0
/datasets    |None          |10000          |None              |None              |1           |0.0
/projects/db |None          |10000          |None              |None              |1           |0.0
/fs2         |None          |20000000       |None              |None              |1           |0.0
/            |None          |None           |None              |None              |1272840819  |2219.625
/bonzo/roy   |None          |None           |None              |10000000          |181470      |0.006
$ vastpy-cli get quotas path=/alon/foo fields=path,used_capacity_tb,used_inodes,soft_limit,hard_limit,soft_limit_inodes,hard_limit_inodes
path      |soft_limit |hard_limit |soft_limit_inodes |hard_limit_inodes |used_inodes |used_capacity_tb
----------+-----------+-----------+------------------+------------------+------------+-----------------+
/alon/foo |5000       |10000      |None              |None              |1           |0.0
```

You can create a read-only user in VMS to share with end users if needed.

**Byron/dua-cli** - A tool to conveniently learn about the disk usage of directories, fast!.

Website [https://lib.rs/crates/dua-cli](https://lib.rs/crates/dua-cli)