diff --git a/pkg/harvester/components/vm-migration/ConfigureMappingsStep.vue b/pkg/harvester/components/vm-migration/ConfigureMappingsStep.vue
index 0cb5370b..75d7ab5c 100644
--- a/pkg/harvester/components/vm-migration/ConfigureMappingsStep.vue
+++ b/pkg/harvester/components/vm-migration/ConfigureMappingsStep.vue
@@ -11,6 +11,10 @@ import { FORKLIFT_NAMESPACE } from '../../config/harvester-map';
 import { buildNetworkMapEntries, buildStorageMapEntries } from '../../utils/forklift';
 import { isInternalStorageClass } from '../../utils/storage-class';
 import MappingColumn from './MappingColumn.vue';
+import StorageDefaultsModal from './StorageDefaultsModal.vue';
+
+const DEFAULT_VOLUME_MODE = 'Filesystem';
+const DEFAULT_ACCESS_MODES = ['ReadWriteMany'];
 
 const props = defineProps({
   providerName:       { type: String, default: '' },
@@ -35,6 +39,10 @@ const allStorageMaps = ref([]);
 const errors = ref([]);
 const loading = ref(true);
 
+// Storage defaults edit modal state.
+const showStorageDefaultsModal = ref(false);
+const editingStorageEntry = ref(null);
+
 const { networkEntries, storageEntries } = toRefs(props.stepData);
 
 const NAMESPACE = FORKLIFT_NAMESPACE;
@@ -105,7 +113,7 @@ const applyNetworkMapTargets = (mapSpec) => {
   });
 };
 
-const applyStorageMapTargets = (mapSpec) => {
+const applyStorageMapTargets = (mapSpec, { markOverridden = false, captureInherited = false } = {}) => {
   if (!mapSpec) {
     return;
   }
@@ -117,6 +125,26 @@ const applyStorageMapTargets = (mapSpec) => {
 
     if (match?.destination?.storageClass) {
       entry.target = match.destination.storageClass;
+
+      if (match.destination.volumeMode) {
+        entry.volumeMode = match.destination.volumeMode;
+
+        if (captureInherited) {
+          entry.inheritedVolumeMode = match.destination.volumeMode;
+        }
+      }
+
+      if (match.destination.accessMode) {
+        entry.accessModes = [match.destination.accessMode];
+
+        if (captureInherited) {
+          entry.inheritedAccessModes = [match.destination.accessMode];
+        }
+      }
+
+      if (markOverridden) {
+        entry.overridden = true;
+      }
     }
   });
 };
@@ -134,12 +162,34 @@ const applyDefaultStorageMap = () => {
     (sm) => sm.metadata.name === `${ props.providerName }-storage-map-default`
   );
 
-  applyStorageMapTargets(defaultMap?.spec?.map);
+  applyStorageMapTargets(defaultMap?.spec?.map, { captureInherited: true });
 };
 
 const allNetworksMapped = computed(() => networkEntries.value.length > 0 && networkEntries.value.every((e) => !!e.target));
 const allStorageMapped = computed(() => storageEntries.value.length > 0 && storageEntries.value.every((e) => !!e.target));
 
+// The "Inherited from provider" hint only appears in the migration plan wizard
+// (where mappings inherit from the provider default), not on the provider creation page.
+const inheritedProviderName = computed(() => (props.useAllProviderData ? '' : props.providerName));
+
+const openStorageDefaults = (entry) => {
+  editingStorageEntry.value = entry;
+  showStorageDefaultsModal.value = true;
+};
+
+const closeStorageDefaults = () => {
+  showStorageDefaultsModal.value = false;
+  editingStorageEntry.value = null;
+};
+
+const applyStorageDefaults = ({ volumeMode, accessModes }) => {
+  if (editingStorageEntry.value) {
+    editingStorageEntry.value.volumeMode = volumeMode;
+    editingStorageEntry.value.accessModes = accessModes;
+    editingStorageEntry.value.overridden = true;
+  }
+};
+
 const canSave = computed(() => {
   if (props.useAllProviderData) {
     return true;
@@ -202,13 +252,18 @@ const buildStorageEntries = () => {
         if (ds && ds.id) {
           if (!datastoreMap[ds.id]) {
             datastoreMap[ds.id] = {
-              name:     ds.name || t('harvester.addons.vmMigration.generic.unknown'),
-              id:       ds.id,
-              type:     ds.type || '',
-              capacity: 0,
-              target:   '',
-              usedBy:   [],
-              _key:     `stor-${ ds.id }`,
+              name:                 ds.name || t('harvester.addons.vmMigration.generic.unknown'),
+              id:                   ds.id,
+              type:                 ds.type || '',
+              capacity:             0,
+              target:               '',
+              volumeMode:           DEFAULT_VOLUME_MODE,
+              accessModes:          [...DEFAULT_ACCESS_MODES],
+              inheritedVolumeMode:  DEFAULT_VOLUME_MODE,
+              inheritedAccessModes: [...DEFAULT_ACCESS_MODES],
+              overridden:           false,
+              usedBy:               [],
+              _key:                 `stor-${ ds.id }`,
             };
           }
 
@@ -238,13 +293,18 @@ const buildNetworkEntriesFromProvider = (networksData) => {
 
 const buildStorageEntriesFromProvider = (datastoresData) => {
   storageEntries.value = (Array.isArray(datastoresData) ? datastoresData : []).map((ds) => ({
-    name:     ds.name || ds.id,
-    id:       ds.id || '',
-    type:     ds.type || '',
-    capacity: ds.capacity || 0,
-    target:   '',
-    usedBy:   [],
-    _key:     `stor-${ ds.id || ds.name }`,
+    name:                 ds.name || ds.id,
+    id:                   ds.id || '',
+    type:                 ds.type || '',
+    capacity:             ds.capacity || 0,
+    target:               '',
+    volumeMode:           DEFAULT_VOLUME_MODE,
+    accessModes:          [...DEFAULT_ACCESS_MODES],
+    inheritedVolumeMode:  DEFAULT_VOLUME_MODE,
+    inheritedAccessModes: [...DEFAULT_ACCESS_MODES],
+    overridden:           false,
+    usedBy:               [],
+    _key:                 `stor-${ ds.id || ds.name }`,
   }));
 };
 
@@ -461,7 +521,7 @@ const init = async() => {
 
   if (!hasExistingStorageTargets) {
     if (props.existingStorageMap?.spec?.map) {
-      applyStorageMapTargets(props.existingStorageMap.spec.map);
+      applyStorageMapTargets(props.existingStorageMap.spec.map, { markOverridden: true });
     } else {
       applyDefaultStorageMap();
     }
@@ -511,6 +571,9 @@ init();
         :placeholder="t('harvester.addons.vmMigration.configureMappings.storageMapping.placeholder')"
         :show-used-by="!useAllProviderData"
         :clearable="useAllProviderData"
+        :show-volume-settings="true"
+        :inherited-provider-name="inheritedProviderName"
+        @edit-defaults="openStorageDefaults"
       >
         <template #source-detail="{ entry }">
           <span
@@ -520,6 +583,19 @@ init();
         </template>
       </MappingColumn>
     </div>
+
+    <StorageDefaultsModal
+      v-if="showStorageDefaultsModal && editingStorageEntry"
+      :storage-class-name="editingStorageEntry.target"
+      :provider-name="providerName"
+      :show-inherited="!!inheritedProviderName"
+      :volume-mode="editingStorageEntry.volumeMode"
+      :access-modes="editingStorageEntry.accessModes"
+      :inherited-volume-mode="editingStorageEntry.inheritedVolumeMode"
+      :inherited-access-modes="editingStorageEntry.inheritedAccessModes"
+      @apply="applyStorageDefaults"
+      @close="closeStorageDefaults"
+    />
   </div>
 </template>
 
diff --git a/pkg/harvester/components/vm-migration/MappingColumn.vue b/pkg/harvester/components/vm-migration/MappingColumn.vue
index 3264b757..f234121d 100644
--- a/pkg/harvester/components/vm-migration/MappingColumn.vue
+++ b/pkg/harvester/components/vm-migration/MappingColumn.vue
@@ -8,15 +8,21 @@ const store = useStore();
 const { t } = useI18n(store);
 
 const props = defineProps({
-  title:       { type: String, required: true },
-  description: { type: String, default: '' },
-  entries:     { type: Array, default: () => [] },
-  options:     { type: Array, default: () => [] },
-  placeholder: { type: String, default: '' },
-  showUsedBy:  { type: Boolean, default: false },
-  clearable:   { type: Boolean, default: false },
+  title:                 { type: String, required: true },
+  description:           { type: String, default: '' },
+  entries:               { type: Array, default: () => [] },
+  options:               { type: Array, default: () => [] },
+  placeholder:           { type: String, default: '' },
+  showUsedBy:            { type: Boolean, default: false },
+  clearable:             { type: Boolean, default: false },
+  // Storage-specific: show the volume/access mode defaults row with an Edit action.
+  showVolumeSettings:    { type: Boolean, default: false },
+  // When set, the defaults row shows an "Inherited from provider" hint (migration plan wizard only).
+  inheritedProviderName: { type: String, default: '' },
 });
 
+const emit = defineEmits(['edit-defaults']);
+
 // Only offer "Remove Map" for entries that already have a target selected;
 // entries without a selection just show the regular options.
 const optionsFor = (entry) => {
@@ -38,6 +44,13 @@ const optionsFor = (entry) => {
     ...props.options,
   ];
 };
+
+const formatModes = (entry) => {
+  const volumeMode = entry.volumeMode || 'Filesystem';
+  const accessModes = (entry.accessModes || []).join(', ');
+
+  return t('harvester.addons.vmMigration.storageDefaults.summary', { volumeMode, accessModes });
+};
 </script>
 
 <template>
@@ -87,6 +100,29 @@ const optionsFor = (entry) => {
               />
             </div>
           </div>
+          <div
+            v-if="showVolumeSettings && entry.target"
+            class="storage-defaults-row"
+          >
+            <div class="storage-defaults">
+              <div class="storage-defaults-info">
+                <span class="storage-defaults-summary">{{ formatModes(entry) }}</span>
+                <span
+                  v-if="inheritedProviderName && !entry.overridden"
+                  class="text-deemphasized storage-defaults-inherited"
+                >
+                  {{ t('harvester.addons.vmMigration.storageDefaults.inherited', { provider: inheritedProviderName }) }}
+                </span>
+              </div>
+              <a
+                role="button"
+                class="storage-defaults-edit"
+                @click.prevent="emit('edit-defaults', entry)"
+              >
+                {{ t('harvester.addons.vmMigration.storageDefaults.edit') }}
+              </a>
+            </div>
+          </div>
           <div v-if="showUsedBy && entry.usedBy && entry.usedBy.length">
             <span class="used-by">
               {{ t('harvester.addons.vmMigration.generic.usedBy') }} <b>{{ entry.usedBy.join(', ') }}</b>
@@ -173,6 +209,41 @@ const optionsFor = (entry) => {
     line-height: 20px;
   }
 
+  .storage-defaults-row {
+    width: 100%;
+  }
+
+  .storage-defaults {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 12px;
+    padding: 8px 12px;
+    border-radius: 4px;
+    background-color: var(--body-bg);
+
+    .storage-defaults-info {
+      display: flex;
+      flex-direction: column;
+      min-width: 0;
+    }
+
+    .storage-defaults-summary {
+      font-size: 13px;
+      line-height: 20px;
+    }
+
+    .storage-defaults-inherited {
+      font-size: 12px;
+      line-height: 18px;
+    }
+
+    .storage-defaults-edit {
+      flex-shrink: 0;
+      cursor: pointer;
+    }
+  }
+
   .bg-light-gray {
     background-color: var(--category-active) !important;
     border: 0;
diff --git a/pkg/harvester/components/vm-migration/StorageDefaultsModal.vue b/pkg/harvester/components/vm-migration/StorageDefaultsModal.vue
new file mode 100644
index 00000000..0777e5d0
--- /dev/null
+++ b/pkg/harvester/components/vm-migration/StorageDefaultsModal.vue
@@ -0,0 +1,173 @@
+<script setup>
+import { ref } from 'vue';
+import { useStore } from 'vuex';
+import { Card } from '@components/Card';
+import LabeledSelect from '@shell/components/form/LabeledSelect';
+import AppModal from '@shell/components/AppModal';
+import { useI18n } from '@shell/composables/useI18n';
+
+const VOLUME_MODE_OPTIONS = ['Filesystem', 'Block'];
+const ACCESS_MODE_OPTIONS = ['ReadWriteOnce', 'ReadWriteMany', 'ReadOnlyMany'];
+
+const props = defineProps({
+  storageClassName:     { type: String, default: '' },
+  providerName:         { type: String, default: '' },
+  showInherited:        { type: Boolean, default: false },
+  volumeMode:           { type: String, default: 'Filesystem' },
+  accessModes:          { type: Array, default: () => ['ReadWriteMany'] },
+  inheritedVolumeMode:  { type: String, default: 'Filesystem' },
+  inheritedAccessModes: { type: Array, default: () => ['ReadWriteMany'] },
+});
+
+const emit = defineEmits(['apply', 'close']);
+
+const store = useStore();
+const { t } = useI18n(store);
+
+const localVolumeMode = ref(props.volumeMode || 'Filesystem');
+const localAccessMode = ref(props.accessModes?.[0] || 'ReadWriteMany');
+
+const volumeModeOptions = VOLUME_MODE_OPTIONS.map((value) => ({ label: value, value }));
+const accessModeOptions = ACCESS_MODE_OPTIONS.map((value) => ({ label: value, value }));
+
+const apply = () => {
+  emit('apply', {
+    volumeMode:  localVolumeMode.value,
+    accessModes: [localAccessMode.value],
+  });
+  emit('close');
+};
+
+// Repopulate the dropdowns with the provider default values; the user then applies.
+const reset = () => {
+  localVolumeMode.value = props.inheritedVolumeMode || 'Filesystem';
+  localAccessMode.value = props.inheritedAccessModes?.[0] || 'ReadWriteMany';
+};
+
+const cancel = () => {
+  emit('close');
+};
+</script>
+
+<template>
+  <app-modal
+    class="storage-defaults-modal"
+    name="storageDefaultsDialog"
+    :width="620"
+    height="auto"
+    :click-to-close="false"
+    @close="cancel"
+  >
+    <Card
+      class="storage-defaults-card"
+      :show-highlight-border="false"
+    >
+      <template #title>
+        <h4 class="text-default-text">
+          {{ t('harvester.addons.vmMigration.storageDefaults.title', { name: storageClassName }) }}
+        </h4>
+      </template>
+
+      <template #body>
+        <p class="text-deemphasized description">
+          <template v-if="showInherited">
+            {{ t('harvester.addons.vmMigration.storageDefaults.descriptionInherited', { name: storageClassName, provider: providerName }) }}
+          </template>
+          <template v-else>
+            {{ t('harvester.addons.vmMigration.storageDefaults.description', { name: storageClassName }) }}
+          </template>
+        </p>
+
+        <div class="settings-box">
+          <LabeledSelect
+            v-model:value="localVolumeMode"
+            class="volume-mode"
+            :label="t('harvester.addons.vmMigration.storageDefaults.volumeMode')"
+            :options="volumeModeOptions"
+            :searchable="false"
+            :clearable="false"
+          />
+
+          <LabeledSelect
+            v-model:value="localAccessMode"
+            class="access-mode"
+            :label="t('harvester.addons.vmMigration.storageDefaults.accessMode')"
+            :options="accessModeOptions"
+            :searchable="false"
+            :clearable="false"
+          />
+        </div>
+      </template>
+
+      <template #actions>
+        <div class="buttons">
+          <button
+            class="btn role-secondary"
+            @click="cancel"
+          >
+            {{ t('harvester.addons.vmMigration.storageDefaults.cancel') }}
+          </button>
+          <div class="right-buttons">
+            <button
+              v-if="showInherited"
+              class="btn role-secondary mr-10"
+              @click="reset"
+            >
+              {{ t('harvester.addons.vmMigration.storageDefaults.resetToProviderDefault') }}
+            </button>
+            <button
+              class="btn role-primary"
+              :disabled="!localAccessMode"
+              @click="apply"
+            >
+              {{ showInherited ? t('harvester.addons.vmMigration.storageDefaults.applyOverride') : t('harvester.addons.vmMigration.storageDefaults.apply') }}
+            </button>
+          </div>
+        </div>
+      </template>
+    </Card>
+  </app-modal>
+</template>
+
+<style lang="scss" scoped>
+  .storage-defaults-modal {
+    z-index: 45;
+  }
+
+  .storage-defaults-card {
+    margin: 0;
+  }
+
+  .description {
+    margin-bottom: 16px;
+    line-height: 20px;
+  }
+
+  .settings-box {
+    display: flex;
+    flex-direction: column;
+    gap: 20px;
+    padding: 16px;
+    border-radius: 6px;
+    background-color: var(--category-active);
+  }
+
+  .volume-mode {
+    max-width: 280px;
+  }
+
+  .access-mode {
+    max-width: 280px;
+  }
+
+  .buttons {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    width: 100%;
+
+    .right-buttons {
+      display: flex;
+    }
+  }
+</style>
diff --git a/pkg/harvester/l10n/en-us.yaml b/pkg/harvester/l10n/en-us.yaml
index 5e2e4417..caeca190 100644
--- a/pkg/harvester/l10n/en-us.yaml
+++ b/pkg/harvester/l10n/en-us.yaml
@@ -1982,6 +1982,19 @@ harvester:
           description: Map VMware datastores to Harvester storage classes
           placeholder: Choose a Harvester Storage Class
           template: Use existing storage mapping as template
+      storageDefaults:
+        title: 'Storage defaults — {name}'
+        description: 'Set the volume mode and access modes applied to every datastore in this storage map that maps to {name}.'
+        descriptionInherited: 'Applies to every datastore in this storage map that maps to {name}. The provider default for {provider} stays unchanged.'
+        summary: 'Volume mode : {volumeMode} · Access mode : {accessModes}'
+        inherited: 'Inherited from provider {provider}'
+        volumeMode: Volume Mode
+        accessMode: Access Mode
+        edit: Edit
+        cancel: Cancel
+        apply: Apply
+        resetToProviderDefault: Reset to Provider Default
+        applyOverride: Apply Override
       reviewMigration:
         title: Review Migration Plan
         description: Confirm your migration settings before starting the transfer of VMs to the target cluster.
diff --git a/pkg/harvester/pages/c/_cluster/vm-migration/provider-wizard.vue b/pkg/harvester/pages/c/_cluster/vm-migration/provider-wizard.vue
index 196453c4..2790424e 100644
--- a/pkg/harvester/pages/c/_cluster/vm-migration/provider-wizard.vue
+++ b/pkg/harvester/pages/c/_cluster/vm-migration/provider-wizard.vue
@@ -5,6 +5,7 @@ import CruResource from '@shell/components/CruResource';
 import Loading from '@shell/components/Loading';
 import { SECRET } from '@shell/config/types';
 import { useI18n } from '@shell/composables/useI18n';
+import { exceptionToErrorsArray, stringify } from '@shell/utils/error';
 import ConfigureProviderStep from '@pkg/harvester/components/vm-migration/ConfigureProviderStep.vue';
 import ConfigureMappingsStep from '@pkg/harvester/components/vm-migration/ConfigureMappingsStep.vue';
 import { PRODUCT_NAME } from '@pkg/harvester/config/harvester';
@@ -163,7 +164,7 @@ const onFinish = async(buttonCb) => {
     buttonCb(true);
     currentRouter().push(providerListLocation);
   } catch (err) {
-    errors.value = [err instanceof Error ? err.message : String(err)];
+    errors.value = exceptionToErrorsArray(err).map((e) => (typeof e === 'string' ? e : stringify(e)));
     buttonCb(false);
   }
 };
@@ -233,7 +234,7 @@ const init = async() => {
       // Maps may not exist yet
     }
   } catch (err) {
-    errors.value = [t('harvester.addons.vmMigration.errors.failedLoadProvider', { error: err.message || err })];
+    errors.value = [t('harvester.addons.vmMigration.errors.failedLoadProvider', { error: err.message || stringify(err) })];
   }
 
   initialLoading.value = false;
diff --git a/pkg/harvester/utils/forklift.js b/pkg/harvester/utils/forklift.js
index 8387c5ec..502d74c1 100644
--- a/pkg/harvester/utils/forklift.js
+++ b/pkg/harvester/utils/forklift.js
@@ -73,8 +73,21 @@ export function buildNetworkMapEntries(entries = [], defaultNamespace) {
 export function buildStorageMapEntries(entries = []) {
   return entries
     .filter((entry) => !!entry.target)
-    .map((entry) => ({
-      source:      { name: entry.name, id: entry.id },
-      destination: { storageClass: entry.target },
-    }));
+    .map((entry) => {
+      const destination = { storageClass: entry.target };
+
+      if (entry.volumeMode) {
+        destination.volumeMode = entry.volumeMode;
+      }
+
+      // Forklift StorageMap destination expects a single `accessMode` value.
+      if (Array.isArray(entry.accessModes) && entry.accessModes.length) {
+        destination.accessMode = entry.accessModes[0];
+      }
+
+      return {
+        source: { name: entry.name, id: entry.id },
+        destination,
+      };
+    });
 }