hashicorp/nomad · error

oom_score_adj must not be negative

Error message

oom_score_adj must not be negative

What it means

rawexec's TaskConfig.validate() rejects a negative oom_score_adj. The value maps directly to the Linux kernel's /proc/<pid>/oom_score_adj, which must be within [-1000, 1000]; Nomad's driver enforces non-negative values to prevent tasks from being made immune to the OOM killer.

Source

Thrown at drivers/rawexec/driver.go:198

	// OOMScoreAdj sets the oom_score_adj on Linux systems
	OOMScoreAdj int `codec:"oom_score_adj"`

	// WorkDir sets the working directory of the task
	WorkDir string `codec:"work_dir"`

	//DeniedEnvvars enables the removal of specified environment variables from a given job environment
	DeniedEnvvars []string `codec:"denied_envvars"`
}

func (t *TaskConfig) validate() error {
	// ensure only one of cgroups_v1_override and cgroups_v2_override have been
	// configured; must check here because task config validation cannot happen
	// on the server.
	if len(t.OverrideCgroupV1) > 0 && t.OverrideCgroupV2 != "" {
		return errors.New("only one of cgroups_v1_override and cgroups_v2_override may be set")
	}
	if t.OOMScoreAdj < 0 {
		return errors.New("oom_score_adj must not be negative")
	}
	if t.WorkDir != "" && !filepath.IsAbs(t.WorkDir) {
		return errors.New("work_dir must be an absolute path")
	}
	return nil
}

// TaskState is the state which is encoded in the handle returned in
// StartTask. This information is needed to rebuild the task state and handler
// during recovery.
type TaskState struct {
	ReattachConfig *pstructs.ReattachConfig
	TaskConfig     *drivers.TaskConfig
	Pid            int
	StartedAt      time.Time
}

// NewRawExecDriver returns a new DriverPlugin implementation

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Set oom_score_adj to 0 or a positive value (e.g. 100–1000) as required by the driver
2. Remove oom_score_adj entirely to inherit the default score
3. If the process truly must be OOM-protected, run it outside Nomad or adjust at the system level with the appropriate privileges
4. Review Nomad docs for the allowed oom_score_adj range in your version

Example fix

// before
config {
  command = "/bin/app"
  oom_score_adj = -500
}
// after
config {
  command = "/bin/app"
  oom_score_adj = 500
}

func checkOomScoreAdj(v *int) error {
    if v != nil && *v < 0 {
        return errors.New("oom_score_adj must be >= 0")
    }
    return nil
}

func validOomScore(v int) bool { return v >= 0 }

When it happens

Trigger: Submitting a rawexec task with oom_score_adj set to a negative integer in the driver config; validate() runs at task-config parse time on the client.

Common situations: Operators trying to protect critical processes from the OOM killer copy Linux admin advice that uses negative values; typo like "oom_score_adj = -100" from an older systemd unit config; misunderstanding of Nomad's intentionally stricter validation.

Related errors

• only one of cgroups_v1_override and cgroups_v2_override may
• work_dir must be an absolute path
• failed to parse config:
• rpc.dial_timeout must be greater than or equal to zero
• client_introduction.enforcement must be set

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/f8c2021b35765533. Report an issue: GitHub.