diff --git a/packages/system/cilium/Makefile b/packages/system/cilium/Makefile
index fa90cf568..b221bb3da 100644
--- a/packages/system/cilium/Makefile
+++ b/packages/system/cilium/Makefile
@@ -6,6 +6,12 @@ export NAMESPACE=cozy-$(NAME)
 include ../../../hack/common-envs.mk
 include ../../../hack/package.mk
 
+# hack/helm-unit-tests.sh discovers work by probing for this target, so a
+# package without one is skipped in silence however many suites sit under
+# tests/.
+test:
+	helm unittest .
+
 update:
 	rm -rf charts
 	helm repo add cilium https://helm.cilium.io/
diff --git a/packages/system/cilium/tests/agent_resources_test.yaml b/packages/system/cilium/tests/agent_resources_test.yaml
new file mode 100644
index 000000000..3ccd1421d
--- /dev/null
+++ b/packages/system/cilium/tests/agent_resources_test.yaml
@@ -0,0 +1,81 @@
+suite: cilium-agent memory requests and limits
+
+# The cilium-agent DaemonSet ran with no resources at all, which put it in the
+# Talos userspace OOM handler's victim set: that handler (v1.12+) only ever
+# selects cgroups that lack memory.max, and picks by QoS class rather than by
+# what caused the pressure. Losing cilium-agent on a node takes that node's
+# datapath programming with it.
+#
+# The limit is what sets memory.max, and it is set on the POD cgroup only when
+# EVERY container in the pod has one — so all seven are asserted here, not just
+# the agent. Five of the init containers take their values from initResources;
+# install-cni-binaries carries upstream's own cni.resources and is asserted to
+# document that it is already covered rather than overlooked.
+#
+# Both keys are set from the umbrella values.yaml against the vendored subchart.
+# An upstream bump that renames or relocates either one renders nothing and
+# leaves no other trace, silently returning the pod to the victim set; catching
+# that is the main thing these assertions are for.
+release:
+  name: cilium
+  namespace: cozy-cilium
+tests:
+  - it: cilium-agent declares a memory limit and request
+    template: charts/cilium/templates/cilium-agent/daemonset.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="cilium-agent")].resources.limits.memory
+          value: 4Gi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="cilium-agent")].resources.requests.memory
+          value: 256Mi
+
+  # Asserted one container at a time. A negated matcher over the init container
+  # list reads as if it covers them all but passes vacuously, so each limit is
+  # pinned explicitly instead.
+  - it: every cilium-agent init container declares a memory limit
+    template: charts/cilium/templates/cilium-agent/daemonset.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="config")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="mount-cgroup")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="apply-sysctl-overwrites")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="mount-bpf-fs")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="clean-cilium-state")].resources.limits.memory
+          value: 256Mi
+      # Upstream's cni.resources, not initResources — pinned so a bump that
+      # drops it is caught here rather than by a pod that quietly loses
+      # memory.max.
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="install-cni-binaries")].resources.limits.memory
+          value: 1Gi
+
+  # cilium-envoy is a second DaemonSet on the same nodes. Its limit predates
+  # this suite; it is pinned here because the pod-level argument above applies
+  # to it identically.
+  - it: cilium-envoy declares a memory limit and request
+    template: charts/cilium/templates/cilium-envoy/daemonset.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="cilium-envoy")].resources.limits.memory
+          value: 1Gi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="cilium-envoy")].resources.requests.memory
+          value: 512Mi
diff --git a/packages/system/cilium/values.yaml b/packages/system/cilium/values.yaml
index 74ce563e3..5e1ef9630 100644
--- a/packages/system/cilium/values.yaml
+++ b/packages/system/cilium/values.yaml
@@ -38,6 +38,30 @@ cilium:
         memory: 512Mi
       limits:
         memory: 1Gi
+  # The cilium-agent DaemonSet had the same gap the envoy DaemonSet above
+  # already closed. Beyond the node-headroom argument, a memory limit is what
+  # sets memory.max on the pod cgroup, and the Talos userspace OOM handler
+  # (v1.12+) only ever selects cgroups that lack it — so an unlimited agent is
+  # an eviction candidate on every node regardless of what caused the pressure.
+  # 14d peak on a 3-node dev cluster is 575Mi, and the agent grows with
+  # endpoint and policy count, so the limit matches the 4Gi in the upstream
+  # values' own commented example rather than being fitted to that measurement.
+  resources:
+    requests:
+      cpu: 100m
+      memory: 256Mi
+    limits:
+      memory: 4Gi
+  # Shared by the agent's init containers (config, mount-cgroup, mount-bpf-fs,
+  # apply-sysctl-overwrites, clean-cilium-state). All are short-lived setup
+  # steps, but each one still has to carry a limit for the pod cgroup to get
+  # memory.max at all.
+  initResources:
+    requests:
+      cpu: 10m
+      memory: 32Mi
+    limits:
+      memory: 256Mi
   gatewayAPI:
     enabled: true
     # Upstream default is false — Envoy then advertises no ALPN protocols on
diff --git a/packages/system/kubevirt-csi-node/templates/deploy.yaml b/packages/system/kubevirt-csi-node/templates/deploy.yaml
index 4b0afad79..cac1db440 100644
--- a/packages/system/kubevirt-csi-node/templates/deploy.yaml
+++ b/packages/system/kubevirt-csi-node/templates/deploy.yaml
@@ -196,10 +196,17 @@ spec:
             timeoutSeconds: 3
             periodSeconds: 10
             failureThreshold: 5
+          # Limits, not just requests: a memory limit is what sets memory.max on
+          # the pod cgroup, and the Talos userspace OOM handler (v1.12+) only
+          # ever kills cgroups that lack one. Requests alone left this DaemonSet
+          # an eviction candidate on every node whatever caused the pressure.
+          # Every container in the pod needs one for the pod cgroup to get it.
           resources:
             requests:
               memory: 50Mi
               cpu: 10m
+            limits:
+              memory: 512Mi
         - name: csi-node-driver-registrar
           image: quay.io/openshift/origin-csi-node-driver-registrar:latest
           args:
@@ -224,6 +231,8 @@ spec:
             requests:
               memory: 20Mi
               cpu: 5m
+            limits:
+              memory: 128Mi
         - name: csi-liveness-probe
           image: quay.io/openshift/origin-csi-livenessprobe:latest
           args:
@@ -237,6 +246,8 @@ spec:
             requests:
               memory: 20Mi
               cpu: 5m
+            limits:
+              memory: 128Mi
       volumes:
         - name: kubelet-dir
           hostPath:
diff --git a/packages/system/kubevirt-csi-node/tests/daemonset_resources_test.yaml b/packages/system/kubevirt-csi-node/tests/daemonset_resources_test.yaml
new file mode 100644
index 000000000..6c3bf5368
--- /dev/null
+++ b/packages/system/kubevirt-csi-node/tests/daemonset_resources_test.yaml
@@ -0,0 +1,48 @@
+suite: csi-node DaemonSet memory limits
+
+# The node DaemonSet carried requests but no limits, which leaves it Burstable
+# rather than Guaranteed-of-a-cgroup-limit: a memory limit is what sets
+# memory.max on the pod cgroup, and the Talos userspace OOM handler (v1.12+)
+# only ever selects cgroups that lack it. Requests alone did not take the pod
+# out of the victim set.
+#
+# memory.max lands on the POD cgroup only when EVERY container has a limit, so
+# all three are asserted rather than the driver alone — one limit-free sidecar
+# would put the whole pod back in the victim set while the other two assertions
+# still passed, which is precisely the failure this suite exists to catch.
+
+templates:
+  - templates/deploy.yaml
+
+tests:
+  - it: every csi-node container declares a memory limit
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-driver")].resources.limits.memory
+          value: 512Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-node-driver-registrar")].resources.limits.memory
+          value: 128Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-liveness-probe")].resources.limits.memory
+          value: 128Mi
+
+  # Pinned alongside the limits because they are what the limits were sized
+  # against; a drift in either direction is worth catching.
+  - it: csi-node containers keep their memory requests
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-driver")].resources.requests.memory
+          value: 50Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-node-driver-registrar")].resources.requests.memory
+          value: 20Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="csi-liveness-probe")].resources.requests.memory
+          value: 20Mi
diff --git a/packages/system/kubevirt/templates/kubevirt-cr.yaml b/packages/system/kubevirt/templates/kubevirt-cr.yaml
index 10754aad3..d0738b29e 100644
--- a/packages/system/kubevirt/templates/kubevirt-cr.yaml
+++ b/packages/system/kubevirt/templates/kubevirt-cr.yaml
@@ -42,6 +42,19 @@ spec:
     - Evict
     batchEvictionInterval: 1m
     batchEvictionSize: 10
-  customizeComponents: {}
+  # virt-handler is a node DaemonSet and ran BestEffort. The Talos userspace OOM
+  # handler (v1.12+) only ever kills cgroups with no memory.max, and picks its
+  # victim by QoS class rather than by what caused the pressure — so virt-handler
+  # was an eviction candidate on every node, and losing it stops VM lifecycle
+  # operations there. virt-operator owns the DaemonSet, so resources cannot be
+  # set from chart values; customizeComponents.patches is the supported seam.
+  # 14d peak 207Mi on a 3-node dev cluster; grows with VMs per node.
+  customizeComponents:
+    patches:
+    - resourceName: virt-handler
+      resourceType: DaemonSet
+      type: strategic
+      patch: |
+        {"spec":{"template":{"spec":{"containers":[{"name":"virt-handler","resources":{"requests":{"cpu":"100m","memory":"128Mi"},"limits":{"memory":"2Gi"}}}]}}}}
   imagePullPolicy: IfNotPresent
   monitorNamespace: tenant-root
diff --git a/packages/system/kubevirt/tests/kubevirt_cr_test.yaml b/packages/system/kubevirt/tests/kubevirt_cr_test.yaml
index eda3218ca..9ea588810 100644
--- a/packages/system/kubevirt/tests/kubevirt_cr_test.yaml
+++ b/packages/system/kubevirt/tests/kubevirt_cr_test.yaml
@@ -92,3 +92,27 @@ tests:
           path: spec.configuration.mediatedDevicesConfiguration.mediatedDeviceTypes
           value:
           - nvidia-740
+
+  # virt-operator owns the virt-handler DaemonSet, so resources cannot come from
+  # chart values — customizeComponents.patches is the only seam. virt-handler ran
+  # BestEffort on every node, and the Talos userspace OOM handler (v1.12+) only
+  # kills cgroups with no memory.max, so it was a standing eviction candidate.
+  # Pin the patch: a malformed or dropped entry fails silently at runtime, since
+  # virt-operator simply reconciles the DaemonSet without the resources.
+  - it: patches virt-handler with memory requests and limits
+    asserts:
+      - equal:
+          path: spec.customizeComponents.patches[0].resourceName
+          value: virt-handler
+      - equal:
+          path: spec.customizeComponents.patches[0].resourceType
+          value: DaemonSet
+      - equal:
+          path: spec.customizeComponents.patches[0].type
+          value: strategic
+      - matchRegex:
+          path: spec.customizeComponents.patches[0].patch
+          pattern: '"limits":\{"memory":"2Gi"\}'
+      - matchRegex:
+          path: spec.customizeComponents.patches[0].patch
+          pattern: '"requests":\{"cpu":"100m","memory":"128Mi"\}'
diff --git a/packages/system/linstor/templates/satellites-cozy.yaml b/packages/system/linstor/templates/satellites-cozy.yaml
index e6f877a04..7897189f4 100644
--- a/packages/system/linstor/templates/satellites-cozy.yaml
+++ b/packages/system/linstor/templates/satellites-cozy.yaml
@@ -14,6 +14,24 @@ spec:
       containers:
       - name: linstor-satellite
         image: {{ .Values.piraeusServer.image.repository }}:{{ .Values.piraeusServer.image.tag }}
+        # The satellite DaemonSet ran BestEffort on every storage node, which
+        # made it a standing victim for the Talos userspace OOM handler
+        # (v1.12+): that handler only ever kills cgroups with no memory.max, and
+        # picks by QoS class rather than by what caused the pressure. A tenant
+        # workload thrashing against its own limit would get the satellite
+        # killed, taking DRBD connections down with it.
+        #
+        # Note this is the opposite call from linstor-controller, which is
+        # deliberately left limit-free in values.yaml (a JVM that must not be
+        # OOM-killed mid-operation). The satellite is a Go binary with a bounded
+        # working set, so a generous limit costs nothing and buys immunity.
+        # 14d peak 368Mi on a 3-node dev cluster; grows with resource count.
+        resources:
+          requests:
+            cpu: 100m
+            memory: 128Mi
+          limits:
+            memory: 2Gi
         startupProbe:
           tcpSocket:
             port: linstor
diff --git a/packages/system/linstor/templates/satellites-plunger.yaml b/packages/system/linstor/templates/satellites-plunger.yaml
index ab71298bf..00018faf6 100644
--- a/packages/system/linstor/templates/satellites-plunger.yaml
+++ b/packages/system/linstor/templates/satellites-plunger.yaml
@@ -12,6 +12,17 @@ spec:
       containers:
       - name: plunger
         image: {{ .Values.piraeusServer.image.repository }}:{{ .Values.piraeusServer.image.tag }}
+        # Sidecars in the satellite pod. Every container needs a memory limit
+        # for the pod cgroup to get memory.max, which is what keeps the pod out
+        # of the Talos userspace OOM handler's victim set — one limit-free
+        # sidecar is enough to put the whole satellite pod back in it.
+        # 14d peaks on a 3-node dev cluster: plunger 18Mi, drbd-logger 5Mi.
+        resources:
+          requests:
+            cpu: 10m
+            memory: 32Mi
+          limits:
+            memory: 128Mi
         command:
         - "/scripts/plunger-satellite.sh"
         securityContext:
@@ -49,6 +60,12 @@ spec:
           readOnly: true
       - name: drbd-logger
         image: {{ .Values.piraeusServer.image.repository }}:{{ .Values.piraeusServer.image.tag }}
+        resources:
+          requests:
+            cpu: 10m
+            memory: 32Mi
+          limits:
+            memory: 128Mi
         command:
         - "/scripts/plunger-drbd-logger.sh"
         securityContext:
diff --git a/packages/system/linstor/tests/satellites_test.yaml b/packages/system/linstor/tests/satellites_test.yaml
new file mode 100644
index 000000000..6e4935637
--- /dev/null
+++ b/packages/system/linstor/tests/satellites_test.yaml
@@ -0,0 +1,39 @@
+suite: satellite pod resource limits
+
+# The satellite DaemonSet ran BestEffort, which made it a standing victim for the
+# Talos userspace OOM handler (v1.12+): that handler only ever kills cgroups with
+# no memory.max, and picks its victim by QoS class rather than by what caused the
+# pressure. A tenant workload thrashing against its own limit would get the
+# satellite killed, taking DRBD connections on that node down with it.
+#
+# Every container in the pod needs a limit for the pod cgroup to get memory.max,
+# so the plunger sidecars are pinned alongside the satellite itself — one
+# limit-free sidecar is enough to put the whole pod back in the victim set.
+#
+# Note this is the opposite call from linstor-controller, which cluster_test.yaml
+# pins as deliberately limit-free (a JVM that must not be OOM-killed mid-operation).
+
+templates:
+  - templates/satellites-cozy.yaml
+  - templates/satellites-plunger.yaml
+
+tests:
+  - it: satellite declares a memory limit and request
+    template: templates/satellites-cozy.yaml
+    asserts:
+      - equal:
+          path: spec.podTemplate.spec.containers[?(@.name=="linstor-satellite")].resources.limits.memory
+          value: 2Gi
+      - equal:
+          path: spec.podTemplate.spec.containers[?(@.name=="linstor-satellite")].resources.requests.memory
+          value: 128Mi
+
+  - it: plunger sidecars declare memory limits
+    template: templates/satellites-plunger.yaml
+    asserts:
+      - equal:
+          path: spec.podTemplate.spec.containers[?(@.name=="plunger")].resources.limits.memory
+          value: 128Mi
+      - equal:
+          path: spec.podTemplate.spec.containers[?(@.name=="drbd-logger")].resources.limits.memory
+          value: 128Mi
diff --git a/packages/system/metallb/tests/metallb_test.yaml b/packages/system/metallb/tests/metallb_test.yaml
index 29f9bdc28..3af5ad68e 100644
--- a/packages/system/metallb/tests/metallb_test.yaml
+++ b/packages/system/metallb/tests/metallb_test.yaml
@@ -185,3 +185,49 @@ tests:
       - equal:
           path: metadata.name
           value: metallb-frr-k8s
+
+  # Both node DaemonSets must carry a memory limit. That limit is what sets
+  # memory.max on the pod cgroup, and the Talos userspace OOM handler (v1.12+)
+  # only ever kills cgroups that lack one — a regression here silently puts the
+  # speaker back in the victim set, which is the failure this pins against.
+  - it: speaker declares a memory limit and request
+    template: charts/metallb/templates/speaker.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[0].resources.limits.memory
+          value: 512Mi
+      - equal:
+          path: spec.template.spec.containers[0].resources.requests.memory
+          value: 64Mi
+
+  - it: every frr-k8s long-running container declares a memory limit
+    template: charts/metallb/charts/frr-k8s/templates/controller.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    # Asserted one container at a time. A negated matcher over the container
+    # list looks like it covers all five but passes vacuously, so each limit is
+    # pinned explicitly instead.
+    #
+    # The four cp-* initContainers are intentionally not asserted: upstream
+    # hardcodes them with no resources knob, so they rely on the
+    # operator-managed namespace LimitRange instead.
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="controller")].resources.limits.memory
+          value: 512Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="frr")].resources.limits.memory
+          value: 512Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="reloader")].resources.limits.memory
+          value: 128Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="frr-metrics")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="frr-status")].resources.limits.memory
+          value: 256Mi
diff --git a/packages/system/metallb/values.yaml b/packages/system/metallb/values.yaml
index 60d31c6cd..209948673 100644
--- a/packages/system/metallb/values.yaml
+++ b/packages/system/metallb/values.yaml
@@ -42,6 +42,22 @@ metallb:
     image:
       repository: ghcr.io/cozystack/cozystack/metallb-speaker
       tag: v1.6.0@sha256:61ab7e2381f0897607b15df7cb5ba4d51a947c261c1c197fcda3b79c7a280016
+    # A memory limit is what sets memory.max on the pod cgroup, and the Talos
+    # userspace OOM handler (v1.12+) only ever kills cgroups that lack it. The
+    # speaker ran BestEffort, so it was picked as the victim whenever a tenant
+    # workload drove node memory PSI — the pressure and the victim being
+    # unrelated by design. See the same block on every node DaemonSet below.
+    #
+    # Requests come from observed usage (14d peak 97Mi on a 3-node dev cluster);
+    # limits are deliberately loose, sized as a runaway backstop rather than a
+    # fitted ceiling, because undersizing here converts a rare pressure-driven
+    # kill into a deterministic one.
+    resources:
+      requests:
+        cpu: 50m
+        memory: 64Mi
+      limits:
+        memory: 512Mi
   # The vendored metallb chart's values.yaml leaves `frr-k8s.prometheus:` as
   # a YAML block containing only commented examples — it parses to null.
   # Helm-controller's deep-merge then writes that null over the frr-k8s
@@ -62,3 +78,47 @@ metallb:
         enabled: false
       podMonitor:
         enabled: false
+    # Same reasoning as speaker.resources above. frr-k8s is the sibling node
+    # DaemonSet that actually speaks BGP, so it shares the speaker's exposure.
+    # 14d peaks on a 3-node dev cluster: controller ~124Mi, frr 43Mi,
+    # frr-metrics 49Mi, frr-status 31Mi, reloader 7Mi.
+    #
+    # The four cp-* init containers are NOT covered here: the upstream chart
+    # hardcodes them with no resources knob, so the pod-level memory.max still
+    # depends on the default LimitRange the operator maintains in every system
+    # namespace. Lifting that needs an upstream change in metallb/frr-k8s.
+    frrk8s:
+      resources:
+        requests:
+          cpu: 50m
+          memory: 64Mi
+        limits:
+          memory: 512Mi
+      frr:
+        resources:
+          requests:
+            cpu: 50m
+            memory: 64Mi
+          limits:
+            memory: 512Mi
+      reloader:
+        resources:
+          requests:
+            cpu: 10m
+            memory: 16Mi
+          limits:
+            memory: 128Mi
+      frrMetrics:
+        resources:
+          requests:
+            cpu: 10m
+            memory: 32Mi
+          limits:
+            memory: 256Mi
+      frrStatus:
+        resources:
+          requests:
+            cpu: 10m
+            memory: 32Mi
+          limits:
+            memory: 256Mi
diff --git a/packages/system/monitoring-agents/tests/node_daemonset_resources_test.yaml b/packages/system/monitoring-agents/tests/node_daemonset_resources_test.yaml
new file mode 100644
index 000000000..f057bee84
--- /dev/null
+++ b/packages/system/monitoring-agents/tests/node_daemonset_resources_test.yaml
@@ -0,0 +1,37 @@
+suite: node DaemonSet memory requests and limits
+
+# fluent-bit and node-exporter both run on every node and both ran BestEffort.
+# The Talos userspace OOM handler (v1.12+) only ever selects cgroups that lack
+# memory.max, and it picks its victim by QoS class rather than by what caused
+# the pressure — so either one could be killed for a tenant workload thrashing
+# against its own limit, on a node that was otherwise healthy.
+#
+# A memory limit is the only thing that sets memory.max, so the limits below are
+# the load-bearing assertions; the requests are pinned alongside them because
+# they are what the values were sized from and a silent drift in either
+# direction is worth catching. Both are set from the umbrella values.yaml, which
+# means an upstream subchart bump that renames or moves the key would render
+# nothing at all and leave no other trace — exactly what these pin against.
+release:
+  name: monitoring-agents
+  namespace: cozy-monitoring
+tests:
+  - it: fluent-bit declares a memory limit and request
+    template: charts/fluent-bit/templates/daemonset.yaml
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="fluent-bit")].resources.limits.memory
+          value: 1Gi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="fluent-bit")].resources.requests.memory
+          value: 128Mi
+
+  - it: node-exporter declares a memory limit and request
+    template: charts/prometheus-node-exporter/templates/daemonset.yaml
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="node-exporter")].resources.limits.memory
+          value: 256Mi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="node-exporter")].resources.requests.memory
+          value: 32Mi
diff --git a/packages/system/monitoring-agents/values.yaml b/packages/system/monitoring-agents/values.yaml
index 4357db276..0770e1deb 100644
--- a/packages/system/monitoring-agents/values.yaml
+++ b/packages/system/monitoring-agents/values.yaml
@@ -285,6 +285,14 @@ vmagent:
   extraArgs: {}
 
 fluent-bit:
+  # 14d peak 319Mi; scales with log volume, so the limit carries wide headroom.
+  # See the node-DaemonSet note at the bottom of this file.
+  resources:
+    requests:
+      cpu: 50m
+      memory: 128Mi
+    limits:
+      memory: 1Gi
   rbac:
     eventsAccess: true
   # Relax probe timing to survive a loaded install. Fluent-bit's HTTP server on
@@ -445,3 +453,19 @@ fluent-bit:
 scrapeRules:
   etcd:
     enabled: false
+
+# Node DaemonSets: a memory limit is what sets memory.max on the pod cgroup, and
+# the Talos userspace OOM handler (v1.12+) only ever kills cgroups that lack one.
+# Both of these ran BestEffort on every node, so they were eviction candidates
+# whenever a tenant workload drove node memory PSI. Requests come from observed
+# usage (14d peak on a 3-node dev cluster); limits are a runaway backstop rather
+# than a fitted ceiling — fluent-bit in particular scales with log volume, which
+# a dev cluster understates.
+prometheus-node-exporter:
+  # 14d peak 42Mi.
+  resources:
+    requests:
+      cpu: 10m
+      memory: 32Mi
+    limits:
+      memory: 256Mi
diff --git a/packages/system/multus/patches/customize-deployment.patch b/packages/system/multus/patches/customize-deployment.patch
index c89e3e9de..e4afcf707 100644
--- a/packages/system/multus/patches/customize-deployment.patch
+++ b/packages/system/multus/patches/customize-deployment.patch
@@ -41,7 +41,30 @@
    labels:
      tier: node
      app: multus
-@@ -160,10 +161,9 @@
+@@ -157,13 +158,33 @@
+         - name: kube-multus
+           image: ghcr.io/k8snetworkplumbingwg/multus-cni:snapshot-thick
+           command: [ "/usr/src/multus-cni/bin/multus-daemon" ]
++          # Upstream sets 50Mi for both the request and the limit. This patch
++          # already raised the request to 100Mi and DELETED the memory limit
++          # outright, leaving only the CPU one -- which left the pod cgroup with
++          # no memory.max, and the Talos userspace OOM handler (v1.12+) only
++          # ever kills cgroups that lack it. So dropping the limit to survive
++          # 50Mi is what made multus an eviction candidate on every node.
++          #
++          # Restore a limit, sized as a backstop rather than a ceiling: 14d peak
++          # is 230Mi on a 3-node dev cluster and this grows with pods per node,
++          # so upstream's 50Mi was never survivable and a fitted value would
++          # trade a rare pressure-driven kill for a deterministic one.
++          #
++          # 1Gi rather than a tighter multiple of that peak, because the peak is
++          # the part least worth trusting here: multus-daemon holds per-pod
++          # state and a 3-node dev cluster understates pods per node more than
++          # it understates anything else measured for this change. The scar this
++          # avoids is the vertical-pod-autoscaler updater, which OOM-looped at a
++          # 110Mi limit for the same reason -- it scaled with pods in the
++          # cluster -- and was given a limit 2.5x its measured request to stop
++          # it. A limit costs nothing until it is hit; only the request reserves.
            resources:
              requests:
                cpu: "100m"
@@ -50,10 +73,26 @@
              limits:
                cpu: "100m"
 -              memory: "50Mi"
++              memory: "1Gi"
            securityContext:
              privileged: true
            terminationMessagePolicy: FallbackToLogsOnError
-@@ -220,6 +220,76 @@
+@@ -209,10 +230,14 @@
+             - "/host/opt/cni/bin"
+             - "-t"
+             - "thick"
++          # Short-lived, but it still needs a limit for the pod cgroup to get
++          # memory.max — the init container counts.
+           resources:
+             requests:
+               cpu: "10m"
+               memory: "15Mi"
++            limits:
++              memory: "128Mi"
+           securityContext:
+             privileged: true
+           terminationMessagePolicy: FallbackToLogsOnError
+@@ -220,6 +245,81 @@
              - name: cnibin
                mountPath: /host/opt/cni/bin
                mountPropagation: Bidirectional
@@ -101,10 +140,15 @@
 +                echo "failed to install:${failed}" > /dev/termination-log 2>/dev/null || true
 +              fi
 +              exit 0
++          # Short-lived, but it still needs a limit for the pod cgroup to get
++          # memory.max — the init container counts. Same 128Mi as the sibling
++          # install-multus-binary above: both only copy binaries to the host.
 +          resources:
 +            requests:
 +              cpu: "10m"
 +              memory: "15Mi"
++            limits:
++              memory: "128Mi"
 +          # cilium's install-cni-binaries copies plugin binaries into this same
 +          # directory with ALL capabilities dropped, in the spc_t domain, with
 +          # no privileged flag. On a node with SELinux enforcing, a container
diff --git a/packages/system/multus/templates/multus-daemonset-thick.yml b/packages/system/multus/templates/multus-daemonset-thick.yml
index 793afbf30..33b1a03e1 100644
--- a/packages/system/multus/templates/multus-daemonset-thick.yml
+++ b/packages/system/multus/templates/multus-daemonset-thick.yml
@@ -158,12 +158,33 @@ spec:
         - name: kube-multus
           image: ghcr.io/cozystack/cozystack/multus-cni:v1.6.0@sha256:0a92e861ead179dd6b46f475fd8878d44b3cfa40ce4d7a8ff92f790d54250d25
           command: [ "/usr/src/multus-cni/bin/multus-daemon" ]
+          # Upstream sets 50Mi for both the request and the limit. This patch
+          # already raised the request to 100Mi and DELETED the memory limit
+          # outright, leaving only the CPU one -- which left the pod cgroup with
+          # no memory.max, and the Talos userspace OOM handler (v1.12+) only
+          # ever kills cgroups that lack it. So dropping the limit to survive
+          # 50Mi is what made multus an eviction candidate on every node.
+          #
+          # Restore a limit, sized as a backstop rather than a ceiling: 14d peak
+          # is 230Mi on a 3-node dev cluster and this grows with pods per node,
+          # so upstream's 50Mi was never survivable and a fitted value would
+          # trade a rare pressure-driven kill for a deterministic one.
+          #
+          # 1Gi rather than a tighter multiple of that peak, because the peak is
+          # the part least worth trusting here: multus-daemon holds per-pod
+          # state and a 3-node dev cluster understates pods per node more than
+          # it understates anything else measured for this change. The scar this
+          # avoids is the vertical-pod-autoscaler updater, which OOM-looped at a
+          # 110Mi limit for the same reason -- it scaled with pods in the
+          # cluster -- and was given a limit 2.5x its measured request to stop
+          # it. A limit costs nothing until it is hit; only the request reserves.
           resources:
             requests:
               cpu: "100m"
               memory: "100Mi"
             limits:
               cpu: "100m"
+              memory: "1Gi"
           securityContext:
             privileged: true
           terminationMessagePolicy: FallbackToLogsOnError
@@ -209,10 +230,14 @@ spec:
             - "/host/opt/cni/bin"
             - "-t"
             - "thick"
+          # Short-lived, but it still needs a limit for the pod cgroup to get
+          # memory.max — the init container counts.
           resources:
             requests:
               cpu: "10m"
               memory: "15Mi"
+            limits:
+              memory: "128Mi"
           securityContext:
             privileged: true
           terminationMessagePolicy: FallbackToLogsOnError
@@ -264,10 +289,15 @@ spec:
                 echo "failed to install:${failed}" > /dev/termination-log 2>/dev/null || true
               fi
               exit 0
+          # Short-lived, but it still needs a limit for the pod cgroup to get
+          # memory.max — the init container counts. Same 128Mi as the sibling
+          # install-multus-binary above: both only copy binaries to the host.
           resources:
             requests:
               cpu: "10m"
               memory: "15Mi"
+            limits:
+              memory: "128Mi"
           # cilium's install-cni-binaries copies plugin binaries into this same
           # directory with ALL capabilities dropped, in the spc_t domain, with
           # no privileged flag. On a node with SELinux enforcing, a container
diff --git a/packages/system/multus/tests/multus_test.yaml b/packages/system/multus/tests/multus_test.yaml
index 04fd5e76c..2855daadc 100644
--- a/packages/system/multus/tests/multus_test.yaml
+++ b/packages/system/multus/tests/multus_test.yaml
@@ -16,6 +16,33 @@ tests:
           path: spec.template.spec.containers[0].image
           pattern: '^ghcr\.io/cozystack/cozystack/multus-cni:'
 
+  # multus runs on every node and had a CPU limit but no memory one, which
+  # leaves the pod cgroup without memory.max. The Talos userspace OOM handler
+  # (v1.12+) only ever selects cgroups that lack it, and picks its victim by QoS
+  # class rather than by what caused the pressure, so multus was an eviction
+  # candidate on every node however healthy it was itself.
+  #
+  # memory.max lands on the POD cgroup only when EVERY container carries a
+  # limit. install-cni-plugins is asserted further down, where the rest of that
+  # container's contract lives; the two below complete the set for a default
+  # render. Keep all three: dropping any one silently returns the whole pod to
+  # the victim set while the other assertions still pass.
+  - it: kube-multus and its binary installer declare memory limits
+    template: templates/multus-daemonset-thick.yml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="kube-multus")].resources.limits.memory
+          value: 1Gi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="kube-multus")].resources.requests.memory
+          value: 100Mi
+      - equal:
+          path: spec.template.spec.initContainers[?(@.name=="install-multus-binary")].resources.limits.memory
+          value: 128Mi
+
   # Guards the cozystack CNI-ordering fix (multusMasterCNI pinned to the cilium
   # conflist) so multus does not auto-detect kube-ovn ahead of cilium at node
   # startup and bypass the cilium CNI chain. This is a hand-edit that lives in
@@ -263,11 +290,23 @@ tests:
       - equal:
           path: spec.template.spec.initContainers[1].resources.requests.memory
           value: 15Mi
-      # And no limits: a memory limit low enough to kill the copy turns staging
-      # into a crashloop, and there is nothing here whose runtime is worth
-      # capping -- it copies fourteen files and exits.
-      - notExists:
-          path: spec.template.spec.initContainers[1].resources.limits
+      # And a memory limit, which this assertion used to deny. The reasoning it
+      # carried -- nothing here is worth capping, it copies fourteen files and
+      # exits -- is about capping runtime, and that is not what the limit is
+      # for. A limit is what puts memory.max on the POD cgroup, and the Talos
+      # userspace OOM handler (v1.12+) only ever selects cgroups that lack it.
+      # The value is per-pod, not per-container: one limit-free container here
+      # leaves the whole multus pod in the victim set, and the system bundle
+      # defaults stageCniPlugins to true, so that is the default deployment.
+      #
+      # The original worry stands on its own terms and is answered by the size,
+      # not by omitting the limit: 128Mi is what would have to be low enough to
+      # kill a `cp` of fourteen small binaries. It matches install-multus-binary
+      # above, which does the same work, and page cache charged to the cgroup is
+      # reclaimable under pressure rather than a cause of OOM.
+      - equal:
+          path: spec.template.spec.initContainers[1].resources.limits.memory
+          value: 128Mi
       # Writing into the hostPath needs uid 0 IN THE CONTAINER. Nothing sets a
       # user today, so it runs as root; a runAsUser or runAsNonRoot at either
       # level turns every install into a permission error, and the script then
diff --git a/packages/system/velero/tests/velero_test.yaml b/packages/system/velero/tests/velero_test.yaml
index 44177de01..135c2f7e6 100644
--- a/packages/system/velero/tests/velero_test.yaml
+++ b/packages/system/velero/tests/velero_test.yaml
@@ -105,3 +105,27 @@ tests:
           path: spec.template.spec.containers[0].livenessProbe
       - notExists:
           path: spec.template.spec.containers[0].readinessProbe
+
+  # node-agent is a DaemonSet and ran BestEffort. A memory limit is what sets
+  # memory.max on the pod cgroup, and the Talos userspace OOM handler (v1.12+)
+  # only ever selects cgroups that lack it — so node-agent was an eviction
+  # candidate on every node whatever caused the pressure, and killing it
+  # mid-backup fails the backup.
+  #
+  # The limit is deliberately loose rather than fitted: measured usage is at
+  # idle, and the agent streams volume data during a backup, which is exactly
+  # when it must not be killed. Set from the umbrella values against the
+  # vendored subchart, so an upstream bump that moves the key would render
+  # nothing and leave no other trace; that is what this pins against.
+  - it: node-agent declares a memory limit and request
+    template: charts/velero/templates/node-agent-daemonset.yaml
+    documentSelector:
+      path: kind
+      value: DaemonSet
+    asserts:
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="node-agent")].resources.limits.memory
+          value: 2Gi
+      - equal:
+          path: spec.template.spec.containers[?(@.name=="node-agent")].resources.requests.memory
+          value: 128Mi
diff --git a/packages/system/velero/values.yaml b/packages/system/velero/values.yaml
index a2c54e615..c3fae2421 100644
--- a/packages/system/velero/values.yaml
+++ b/packages/system/velero/values.yaml
@@ -19,6 +19,20 @@ velero:
         name: plugins
 
   deployNodeAgent: true
+  nodeAgent:
+    # node-agent is a DaemonSet and ran BestEffort. A memory limit is what sets
+    # memory.max on the pod cgroup, and the Talos userspace OOM handler (v1.12+)
+    # only ever kills cgroups that lack one — so it was an eviction candidate on
+    # every node, independent of what caused the pressure. Killing it mid-backup
+    # fails the backup, so the limit is deliberately loose: 14d peak is 121Mi at
+    # idle on a dev cluster, but the agent streams volume data during a backup
+    # and that is exactly when it must not be killed.
+    resources:
+      requests:
+        cpu: 50m
+        memory: 128Mi
+      limits:
+        memory: 2Gi
   configuration:
     # defaultVolumesToFsBackup: true
     # cozy-default BackupStorageLocation lives in the