---
name: "stress"
section: "1"
platform: "linux"
package: "stress"
version: "1.0.7-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/stress"
---

# stress(1)

tool to impose load on and stress test a computer system

## NAME

**stress** - tool to impose load on and stress test a computer system

## SYNOPSIS

```
 stress [OPTIONS]
```

## DESCRIPTION

**stress is a tool that imposes a configurable amount of CPU, memory, I/O,** **or disk stress on a POSIX-compliant operating system and reports any errors** **it detects.**

**stress is not a benchmark. It is a tool used by system administrators to** **evaluate how well their systems will scale, by kernel programmers to evaluate** **perceived performance characteristics, and by systems programmers to expose** **the classes of bugs which only or more frequently manifest themselves when** **the system is under heavy load.**

## OPTIONS

- **-?, --help**

  **Show this help statement.**

- **--version**

  **Show version statement.**

- **-v, --verbose**

  **Be verbose.**

- **-q, --quiet**

  **Be quiet.**

- **-n, --dry-run**

  **Show what would have been done.**

- **-t, --timeout \<N\>**

  **Timeout after N seconds. This option is ignored by -n.**

- **--backoff \<N\>**

  **Wait for factor of microseconds before starting work.**

- **-c, --cpu \<N\>**

  **Spawn N workers spinning on sqrt().**

- **-i, --io \<N\>**

  **Spawn N workers spinning on sync().**

- **-m, --vm \<N\>**

  **Spawn N workers spinning on malloc()/free().**

- **--vm-bytes \<B\>**

  **Malloc B bytes per vm worker (default is 256MB).**

- **--vm-stride \<B\>**

  **Touch a byte every B bytes (default is 4096).**

- **--vm-hang \<N\>**

  **Sleep N secs before free (default none, 0 is inf).**

- **--vm-keep**

  **Redirty memory instead of freeing and reallocating.**

- **-d, --hdd \<N\>**

  **Spawn N workers spinning on write()/unlink().**

- **--hdd-bytes \<B\>**

  **Write B bytes per hdd worker (default is 1GB). The file** **will be created with mkstemp() in the current directory.**

**Note: Numbers may be suffixed with s,m,h,d,y (time) or B,K,M,G (size).**

## EXAMPLES

**The simple case is that you just want to bring the system load average up to an** **arbitrary value. The following forks 13 processes, each of which spins in a** **tight loop calculating the sqrt() of a random number acquired with rand().**

```
    stress -c 13
```

**Long options are supported, as well as is making the output less verbose. The** **following forks 1024 processes, and only reports error messages if any.**

```
    stress --quiet --cpu 1k
```

**To see how your system performs when it is I/O bound, use the -i switch. The** **following forks 4 processes, each of which spins in a tight loop calling** **sync(), which is a system call that flushes memory buffers to disk.**

```
    stress -i 4
```

**Multiple hogs may be combined on the same command line. The following does** **everything the preceding examples did in one command, but also turns up the** **verbosity level as well as showing how to cause the command to self-terminate** **after 1 minute.**

```
    stress -c 13 -i 4 --verbose --timeout 1m
```

**You can write a file of arbitrary length to disk. The file is created with** **mkstemp() in the current directory.**

```
    stress -d 1 --hdd-bytes 13
    Large file support is enabled.
    stress -d 1 --hdd-bytes 3G
```

## AUTHOR

**stress was originally developed by Amos Waterland \<apw@debian.org\> and** **is maintained by some volunteers.**

**Currently, source code and newer versions are available at** **https://github.com/resurrecting-open-source-projects/stress**