Linux disk fill

Linux disk fill fills up the available disk space at a given system path for a specific duration.

Use cases

Linux disk fill:

• Induces heavy disk usage scenario on the target Linux machines.
• Simulates a lack of storage space for the underlying applications in the system.
• Validates application failover and data resiliency in the scenario of low disk space.

note

• This fault can be executed on Ubuntu 16 or higher, Debian 10 or higher, CentOS 7 or higher, RHEL 7 or higher, Fedora 30 or higher, and openSUSE LEAP 15.4 or higher.
• The linux-chaos-infrastructure systemd service should be in an active state, and the infrastructure should be in CONNECTED state.

Fault permissions

The fault uses the root Linux user and root user group.

Fault tunables

Optional tunables

Tunable	Description	Notes
fillPath	System path to fill.	Path to a valid directory.
fillStorage	Amount of storage to be filled.	Can be specified in bytes (b/B), kilobytes (k/K), megabytes (m/M), gigabytes (g/G), or percentage (%) of available storage. If no unit is provided, the value is assumed to be in bytes. Example values: 30m, 1G, 35%, etc. Default: 50%.
dataBlockSize	Size of each data block used to fill up the disk.	Can be specified in bytes (b/B), kilobytes (k/K), megabytes (m/M), or gigabytes (g/G). If no unit is provided, the value is assumed to be in bytes. Example values: 30m, 500k, 1G, etc. Default: 256 KB.
duration	Duration through which chaos is injected into the target resource (in seconds).	Default: 30 s
rampTime	Period to wait before and after injecting chaos (in seconds).	Default: 0 s

Fill path

The fillPath input variable determines the system path to be filled up.

The following YAML snippet illustrates the use of this environment variable:

# specify the fill path
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-disk-fill
  labels:
    name: disk-fill
spec:
  diskFillChaos/inputs:
    fillPath: "/"
    duration: 30

Fill storage

The fillStorage input variable determines the amount of storage space to be filled up at the fillPath path.

The following YAML snippet illustrates the use of this environment variable:

# specify the storage to be filled
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-disk-fill
  labels:
    name: disk-fill
spec:
  diskFillChaos/inputs:
    fillPath: "/"
    fillStorage: 72%
    duration: 30

Data block size

The dataBlockSize input variable determines the size of a single block of data, that is used to fill up the disk. A larger block size results in quick completion of the disk fill operation and vice-versa.

The following YAML snippet illustrates the use of this environment variable:

# specify the data block size
apiVersion: litmuchaos.io/v1alpha1
kind: LinuxFault
metadata:
  name: linux-disk-fill
  labels:
    name: disk-fill
spec:
  diskFillChaos/inputs:
    fillPath: "/"
    fillStorage: 80%
    dataBlockSize: 400k
    duration: 30