diff --git a/cmd/virtwork/main_test.go b/cmd/virtwork/main_test.go
index 653b60b..de0e372 100644
--- a/cmd/virtwork/main_test.go
+++ b/cmd/virtwork/main_test.go
@@ -628,7 +628,7 @@ var _ = Describe("CLI end-to-end scenarios", func() {
 
 	Context("when running with default arguments", func() {
 		It("should create VMs for all workloads", func() {
-			// Default run creates 10 VMs: chaos-process=1 + chaos-network=1 + cpu=1 + memory=1 + disk=1 + database=1 + network=2 + tps=2
+			// Default run creates 11 VMs: chaos-disk=1 + chaos-network=1 + chaos-process=1 + cpu=1 + memory=1 + disk=1 + database=1 + network=2 + tps=2
 			registry := workloads.DefaultRegistry()
 			totalVMs := 0
 			for _, name := range workloads.AllWorkloadNames() {
@@ -646,8 +646,8 @@ var _ = Describe("CLI end-to-end scenarios", func() {
 				Expect(err).NotTo(HaveOccurred())
 				totalVMs += w.VMCount()
 			}
-			// chaos-process=1 + chaos-network=1 + cpu=1 + database=1 + disk=1 + memory=1 + network=2 + tps=2 = 10
-			Expect(totalVMs).To(Equal(10))
+			// chaos-disk=1 + chaos-network=1 + chaos-process=1 + cpu=1 + database=1 + disk=1 + memory=1 + network=2 + tps=2 = 11
+			Expect(totalVMs).To(Equal(11))
 		})
 	})
 
diff --git a/internal/workloads/chaos_disk.go b/internal/workloads/chaos_disk.go
new file mode 100644
index 0000000..47e4713
--- /dev/null
+++ b/internal/workloads/chaos_disk.go
@@ -0,0 +1,141 @@
+// Copyright 2026 Red Hat
+// SPDX-License-Identifier: Apache-2.0
+
+package workloads
+
+import (
+	kubevirtv1 "kubevirt.io/api/core/v1"
+
+	"github.com/opdev/virtwork/internal/config"
+	"github.com/opdev/virtwork/internal/vm"
+)
+
+const chaosDiskScript = `#!/bin/bash
+set -euo pipefail
+
+MOUNT_POINT="${CHAOS_DISK_MOUNT:-/mnt/data}"
+FILL_PERCENT="${CHAOS_DISK_FILL_PERCENT:-90}"
+FILL_FILE="${MOUNT_POINT}/chaos-disk-fill"
+RELEASE_SLEEP="${CHAOS_DISK_RELEASE_SLEEP:-30}"
+FILL_SLEEP="${CHAOS_DISK_FILL_SLEEP:-60}"
+
+while true; do
+    TOTAL_KB=$(df -k "${MOUNT_POINT}" | awk 'NR==2 {print $2}')
+    USED_KB=$(df -k "${MOUNT_POINT}" | awk 'NR==2 {print $3}')
+    TARGET_KB=$(( TOTAL_KB * FILL_PERCENT / 100 ))
+    FILL_KB=$(( TARGET_KB - USED_KB ))
+
+    if [ "${FILL_KB}" -gt 0 ]; then
+        fallocate -l "${FILL_KB}K" "${FILL_FILE}" 2>/dev/null || \
+            dd if=/dev/zero of="${FILL_FILE}" bs=1K count="${FILL_KB}" status=none
+    fi
+
+    sleep "${FILL_SLEEP}"
+
+    rm -f "${FILL_FILE}"
+    sleep "${RELEASE_SLEEP}"
+done
+`
+
+const chaosDiskSystemdUnit = `[Unit]
+Description=Virtwork chaos-disk fill/release workload
+After=network.target local-fs.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/chaos-disk.sh
+Restart=always
+RestartSec=10
+
+[Install]
+WantedBy=multi-user.target
+`
+
+// ChaosDiskWorkload generates cloud-init userdata for a disk fill/release chaos
+// workload using fallocate and dd.
+type ChaosDiskWorkload struct {
+	BaseWorkload
+	DataDiskSize string
+}
+
+// NewChaosDiskWorkload creates a ChaosDiskWorkload with the given configuration,
+// disk size, and SSH credentials.
+func NewChaosDiskWorkload(
+	cfg config.WorkloadConfig,
+	dataDiskSize, sshUser, sshPassword string,
+	sshKeys []string,
+) *ChaosDiskWorkload {
+	return &ChaosDiskWorkload{
+		BaseWorkload: BaseWorkload{
+			Config:            cfg,
+			SSHUser:           sshUser,
+			SSHPassword:       sshPassword,
+			SSHAuthorizedKeys: sshKeys,
+		},
+		DataDiskSize: dataDiskSize,
+	}
+}
+
+// Name returns "chaos-disk".
+func (w *ChaosDiskWorkload) Name() string {
+	return "chaos-disk"
+}
+
+// CloudInitUserdata returns cloud-init YAML that writes a fill/release script
+// and a systemd service that runs it in a loop.
+func (w *ChaosDiskWorkload) CloudInitUserdata() (string, error) {
+	return w.BuildCloudConfig(CloudConfigOpts{
+		WriteFiles: []WriteFile{
+			{
+				Path:        "/usr/local/bin/chaos-disk.sh",
+				Content:     chaosDiskScript,
+				Permissions: "0755",
+			},
+			{
+				Path:        "/etc/systemd/system/virtwork-chaos-disk.service",
+				Content:     chaosDiskSystemdUnit,
+				Permissions: "0644",
+			},
+		},
+		RunCmd: [][]string{
+			{"mkdir", "-p", "/mnt/data"},
+			{"systemctl", "daemon-reload"},
+			{"systemctl", "enable", "--now", "virtwork-chaos-disk.service"},
+		},
+	})
+}
+
+// DataVolumeTemplates returns a DataVolumeTemplateSpec for the data disk.
+func (w *ChaosDiskWorkload) DataVolumeTemplates() []kubevirtv1.DataVolumeTemplateSpec {
+	return []kubevirtv1.DataVolumeTemplateSpec{
+		vm.BuildDataVolumeTemplate("virtwork-chaos-disk-data", w.DataDiskSize),
+	}
+}
+
+// ExtraDisks returns the data disk definition.
+func (w *ChaosDiskWorkload) ExtraDisks() []kubevirtv1.Disk {
+	return []kubevirtv1.Disk{
+		{
+			Name: "datadisk",
+			DiskDevice: kubevirtv1.DiskDevice{
+				Disk: &kubevirtv1.DiskTarget{
+					Bus: "virtio",
+				},
+			},
+		},
+	}
+}
+
+// ExtraVolumes returns the data volume sourced from the DataVolume.
+func (w *ChaosDiskWorkload) ExtraVolumes() []kubevirtv1.Volume {
+	return []kubevirtv1.Volume{
+		{
+			Name: "datadisk",
+			VolumeSource: kubevirtv1.VolumeSource{
+				DataVolume: &kubevirtv1.DataVolumeSource{
+					Name: "virtwork-chaos-disk-data",
+				},
+			},
+		},
+	}
+}
diff --git a/internal/workloads/chaos_disk_test.go b/internal/workloads/chaos_disk_test.go
new file mode 100644
index 0000000..170cfe2
--- /dev/null
+++ b/internal/workloads/chaos_disk_test.go
@@ -0,0 +1,172 @@
+// Copyright 2026 Red Hat
+// SPDX-License-Identifier: Apache-2.0
+
+package workloads_test
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+
+	"github.com/opdev/virtwork/internal/config"
+	"github.com/opdev/virtwork/internal/workloads"
+)
+
+var _ = Describe("ChaosDiskWorkload", func() {
+	var w *workloads.ChaosDiskWorkload
+
+	BeforeEach(func() {
+		w = workloads.NewChaosDiskWorkload(config.WorkloadConfig{
+			Enabled:  true,
+			VMCount:  1,
+			CPUCores: 2,
+			Memory:   "2Gi",
+		}, "10Gi", "virtwork", "", nil)
+	})
+
+	It("should return 'chaos-disk' for Name", func() {
+		Expect(w.Name()).To(Equal("chaos-disk"))
+	})
+
+	It("should include chaos-disk script in write_files", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		Expect(parsed).To(HaveKey("write_files"))
+		files := parsed["write_files"].([]interface{})
+
+		paths := make([]string, len(files))
+		for i, f := range files {
+			paths[i] = f.(map[string]interface{})["path"].(string)
+		}
+		Expect(paths).To(ContainElement("/usr/local/bin/chaos-disk.sh"))
+		Expect(paths).To(ContainElement("/etc/systemd/system/virtwork-chaos-disk.service"))
+	})
+
+	It("should include fallocate in the chaos-disk script", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		files := parsed["write_files"].([]interface{})
+
+		var scriptContent string
+		for _, f := range files {
+			fm := f.(map[string]interface{})
+			if fm["path"] == "/usr/local/bin/chaos-disk.sh" {
+				scriptContent = fm["content"].(string)
+				break
+			}
+		}
+		Expect(scriptContent).NotTo(BeEmpty())
+		Expect(scriptContent).To(ContainSubstring("fallocate"))
+		Expect(scriptContent).To(ContainSubstring("FILL_PERCENT"))
+		Expect(scriptContent).To(ContainSubstring("MOUNT_POINT"))
+	})
+
+	It("should make the chaos-disk script executable", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		files := parsed["write_files"].([]interface{})
+
+		for _, f := range files {
+			fm := f.(map[string]interface{})
+			if fm["path"] == "/usr/local/bin/chaos-disk.sh" {
+				Expect(fm["permissions"]).To(Equal("0755"))
+				return
+			}
+		}
+		Fail("chaos-disk.sh not found in write_files")
+	})
+
+	It("should include systemd unit referencing the script", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		files := parsed["write_files"].([]interface{})
+
+		for _, f := range files {
+			fm := f.(map[string]interface{})
+			if fm["path"] == "/etc/systemd/system/virtwork-chaos-disk.service" {
+				content := fm["content"].(string)
+				Expect(content).To(ContainSubstring("/usr/local/bin/chaos-disk.sh"))
+				Expect(content).To(ContainSubstring("Restart=always"))
+				return
+			}
+		}
+		Fail("systemd unit not found in write_files")
+	})
+
+	It("should produce valid YAML with cloud-config header", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+		Expect(result).To(HavePrefix("#cloud-config\n"))
+
+		parsed := parseYAML(result)
+		Expect(parsed).NotTo(BeNil())
+	})
+
+	It("should have data volume template", func() {
+		dvts := w.DataVolumeTemplates()
+		Expect(dvts).To(HaveLen(1))
+		Expect(dvts[0].Name).To(Equal("virtwork-chaos-disk-data"))
+	})
+
+	It("should have extra disk for data volume", func() {
+		disks := w.ExtraDisks()
+		Expect(disks).To(HaveLen(1))
+		Expect(disks[0].Name).To(Equal("datadisk"))
+
+		volumes := w.ExtraVolumes()
+		Expect(volumes).To(HaveLen(1))
+		Expect(volumes[0].Name).To(Equal("datadisk"))
+	})
+
+	It("should not require a service", func() {
+		Expect(w.RequiresService()).To(BeFalse())
+		Expect(w.ServiceSpec()).To(BeNil())
+	})
+
+	It("should reflect config in VMResources", func() {
+		res := w.VMResources()
+		Expect(res.CPUCores).To(Equal(2))
+		Expect(res.Memory).To(Equal("2Gi"))
+	})
+
+	It("should not require packages (tools pre-installed via golden image)", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		_, hasPackages := parsed["packages"]
+		Expect(hasPackages).To(BeFalse())
+	})
+
+	It("should mount data disk and enable service via runcmd", func() {
+		result, err := w.CloudInitUserdata()
+		Expect(err).NotTo(HaveOccurred())
+
+		parsed := parseYAML(result)
+		Expect(parsed).To(HaveKey("runcmd"))
+
+		cmds := parsed["runcmd"].([]interface{})
+		cmdStrings := make([]string, 0)
+		for _, c := range cmds {
+			parts := c.([]interface{})
+			s := ""
+			for _, p := range parts {
+				if s != "" {
+					s += " "
+				}
+				s += p.(string)
+			}
+			cmdStrings = append(cmdStrings, s)
+		}
+
+		Expect(cmdStrings).To(ContainElement(ContainSubstring("daemon-reload")))
+		Expect(cmdStrings).To(ContainElement(ContainSubstring("virtwork-chaos-disk.service")))
+	})
+})
diff --git a/internal/workloads/registry.go b/internal/workloads/registry.go
index 38105d6..d1924d0 100644
--- a/internal/workloads/registry.go
+++ b/internal/workloads/registry.go
@@ -68,6 +68,9 @@ func DefaultRegistry() Registry {
 		"chaos-network": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
 			return NewChaosNetworkWorkload(cfg, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
 		},
+		"chaos-disk": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
+			return NewChaosDiskWorkload(cfg, opts.DataDiskSize, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
+		},
 		"cpu": func(cfg config.WorkloadConfig, opts *RegistryOpts) Workload {
 			return NewCPUWorkload(cfg, opts.SSHUser, opts.SSHPassword, opts.SSHAuthorizedKeys)
 		},
diff --git a/internal/workloads/registry_test.go b/internal/workloads/registry_test.go
index e305701..f3ac570 100644
--- a/internal/workloads/registry_test.go
+++ b/internal/workloads/registry_test.go
@@ -18,8 +18,19 @@ var _ = Describe("Registry", func() {
 		reg = workloads.DefaultRegistry()
 	})
 
-	It("should have 8 entries registered", func() {
-		Expect(reg.List()).To(HaveLen(8))
+	It("should have 9 entries registered", func() {
+		Expect(reg.List()).To(HaveLen(9))
+	})
+
+	It("should return chaos-disk workload by name", func() {
+		w, err := reg.Get("chaos-disk", config.WorkloadConfig{
+			Enabled:  true,
+			VMCount:  1,
+			CPUCores: 2,
+			Memory:   "2Gi",
+		})
+		Expect(err).NotTo(HaveOccurred())
+		Expect(w.Name()).To(Equal("chaos-disk"))
 	})
 
 	It("should return CPU workload by name", func() {
@@ -103,8 +114,9 @@ var _ = Describe("Registry", func() {
 		_, err := reg.Get("unknown", config.WorkloadConfig{})
 		Expect(err).To(HaveOccurred())
 		Expect(err.Error()).To(ContainSubstring("unknown"))
-		Expect(err.Error()).To(ContainSubstring("chaos-process"))
+		Expect(err.Error()).To(ContainSubstring("chaos-disk"))
 		Expect(err.Error()).To(ContainSubstring("chaos-network"))
+		Expect(err.Error()).To(ContainSubstring("chaos-process"))
 		Expect(err.Error()).To(ContainSubstring("cpu"))
 		Expect(err.Error()).To(ContainSubstring("database"))
 		Expect(err.Error()).To(ContainSubstring("disk"))
@@ -116,6 +128,7 @@ var _ = Describe("Registry", func() {
 	It("should list all names sorted alphabetically", func() {
 		names := reg.List()
 		Expect(names).To(Equal([]string{
+			"chaos-disk",
 			"chaos-network",
 			"chaos-process",
 			"cpu",