diff --git a/Dockerfile b/Dockerfile
index 7129ae2a..2e3d8c4a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,7 @@ ENV VITE_RESTIC_VERSION=${RESTIC_VERSION} \
 
 RUN apk update --no-cache && \
     apk upgrade --no-cache && \
-    apk add --no-cache davfs2=1.6.1-r2 openssh-client fuse3 sshfs tini tzdata
+	apk add --no-cache acl attr cifs-utils davfs2=1.6.1-r2 openssh-client fuse3 sshfs tini tzdata
 
 ENTRYPOINT ["/sbin/tini", "-s", "--"]
 
diff --git a/app/client/modules/volumes/components/create-volume-form.tsx b/app/client/modules/volumes/components/create-volume-form.tsx
index 367c6b81..86ecec24 100644
--- a/app/client/modules/volumes/components/create-volume-form.tsx
+++ b/app/client/modules/volumes/components/create-volume-form.tsx
@@ -66,7 +66,7 @@ type Props = {
 const defaultValuesForType = {
 	directory: { backend: "directory" as const, path: "/" },
 	nfs: { backend: "nfs" as const, port: 2049, version: "4.1" as const },
-	smb: { backend: "smb" as const, port: 445, vers: "3.0" as const },
+	smb: { backend: "smb" as const, port: 445, vers: "3.0" as const, mapToContainerUidGid: false },
 	webdav: { backend: "webdav" as const, port: 80, ssl: false, path: "/webdav" },
 	rclone: { backend: "rclone" as const, path: "/" },
 	sftp: { backend: "sftp" as const, port: 22, path: "/", skipHostKeyCheck: false },
diff --git a/app/client/modules/volumes/components/volume-forms/smb-form.tsx b/app/client/modules/volumes/components/volume-forms/smb-form.tsx
index 89e64b52..34130e9c 100644
--- a/app/client/modules/volumes/components/volume-forms/smb-form.tsx
+++ b/app/client/modules/volumes/components/volume-forms/smb-form.tsx
@@ -168,6 +168,32 @@ export const SMBForm = ({ form }: Props) => {
 					</FormItem>
 				)}
 			/>
+			<FormField
+				control={form.control}
+				name="mapToContainerUidGid"
+				defaultValue={false}
+				render={({ field }) => (
+					<FormItem>
+						<FormLabel>Ownership Mapping</FormLabel>
+						<FormControl>
+							<div className="flex items-center space-x-2">
+								<input
+									type="checkbox"
+									checked={field.value ?? false}
+									onChange={(e) => field.onChange(e.target.checked)}
+									className="rounded border-gray-300"
+								/>
+								<span className="text-sm">Map all files to container user/group</span>
+							</div>
+						</FormControl>
+						<FormDescription>
+							Keep the old behavior by forcing the SMB mount to present every file and directory as owned by the
+							container user and group instead of using server reported ownership.
+						</FormDescription>
+						<FormMessage />
+					</FormItem>
+				)}
+			/>
 			<FormField
 				control={form.control}
 				name="readOnly"
diff --git a/app/server/modules/lifecycle/migrations.ts b/app/server/modules/lifecycle/migrations.ts
index 5dfde9c4..9a4701c9 100644
--- a/app/server/modules/lifecycle/migrations.ts
+++ b/app/server/modules/lifecycle/migrations.ts
@@ -4,6 +4,7 @@ import { v00002 } from "./migrations/00002-isolate-restic-passwords";
 import { v00003 } from "./migrations/00003-assign-organization";
 import { v00004 } from "./migrations/00004-concat-path-name";
 import { v00005 } from "./migrations/00005-split-backup-include-paths";
+import { v00006 } from "./migrations/00006-map-smb-files-to-container-uid-gid";
 import { sql } from "drizzle-orm";
 import { appMetadataTable, usersTable } from "../../db/schema";
 import { db } from "../../db/db";
@@ -38,7 +39,7 @@ type MigrationEntity = {
 	dependsOn?: string[];
 };
 
-const registry: MigrationEntity[] = [v00001, v00002, v00003, v00004, v00005];
+const registry: MigrationEntity[] = [v00001, v00002, v00003, v00004, v00005, v00006];
 
 export const runMigrations = async () => {
 	const userCount = await db.select({ count: sql<number>`count(*)` }).from(usersTable);
diff --git a/app/server/modules/lifecycle/migrations/00006-map-smb-files-to-container-uid-gid.ts b/app/server/modules/lifecycle/migrations/00006-map-smb-files-to-container-uid-gid.ts
new file mode 100644
index 00000000..cdb0d5b9
--- /dev/null
+++ b/app/server/modules/lifecycle/migrations/00006-map-smb-files-to-container-uid-gid.ts
@@ -0,0 +1,44 @@
+import { eq } from "drizzle-orm";
+import { logger } from "@zerobyte/core/node";
+import { db } from "../../../db/db";
+import { volumesTable } from "../../../db/schema";
+import { toMessage } from "~/server/utils/errors";
+
+const execute = async () => {
+	const errors: Array<{ name: string; error: string }> = [];
+	const volumes = await db.query.volumesTable.findMany();
+	let migratedCount = 0;
+
+	for (const volume of volumes) {
+		if (volume.type !== "smb" || volume.config.backend !== "smb" || volume.config.mapToContainerUidGid !== undefined) {
+			continue;
+		}
+
+		try {
+			await db
+				.update(volumesTable)
+				.set({
+					config: { ...volume.config, mapToContainerUidGid: true },
+					updatedAt: Date.now(),
+				})
+				.where(eq(volumesTable.id, volume.id));
+
+			migratedCount += 1;
+		} catch (error) {
+			errors.push({
+				name: `volume:${volume.id}`,
+				error: toMessage(error),
+			});
+		}
+	}
+
+	logger.info(`Migration 00006-map-smb-files-to-container-uid-gid updated ${migratedCount} SMB volumes.`);
+
+	return { success: errors.length === 0, errors };
+};
+
+export const v00006 = {
+	execute,
+	id: "00006-map-smb-files-to-container-uid-gid",
+	type: "maintenance" as const,
+};
diff --git a/app/test/backend-integration/runner.ts b/app/test/backend-integration/runner.ts
index d253a31f..aa608c2c 100644
--- a/app/test/backend-integration/runner.ts
+++ b/app/test/backend-integration/runner.ts
@@ -2,15 +2,15 @@ import crypto from "node:crypto";
 import fs from "node:fs/promises";
 import path from "node:path";
 import { Effect } from "effect";
+import type { VolumeBackend } from "../../../apps/agent/src/volume-host/types";
+import { makeDirectoryBackend } from "../../../apps/agent/src/volume-host/backends/directory";
+import { makeNfsBackend } from "../../../apps/agent/src/volume-host/backends/nfs";
+import { makeRcloneBackend } from "../../../apps/agent/src/volume-host/backends/rclone";
+import { makeSftpBackend } from "../../../apps/agent/src/volume-host/backends/sftp";
+import { makeSmbBackend } from "../../../apps/agent/src/volume-host/backends/smb";
+import { makeWebdavBackend } from "../../../apps/agent/src/volume-host/backends/webdav";
 import { createRestic } from "@zerobyte/core/restic/server";
 import { RCLONE_CONFIG_FILE } from "~/server/core/constants";
-import type { VolumeBackend } from "~/server/modules/backends/backend";
-import { makeDirectoryBackend } from "~/server/modules/backends/directory/directory-backend";
-import { makeNfsBackend } from "~/server/modules/backends/nfs/nfs-backend";
-import { makeRcloneBackend } from "~/server/modules/backends/rclone/rclone-backend";
-import { makeSftpBackend } from "~/server/modules/backends/sftp/sftp-backend";
-import { makeSmbBackend } from "~/server/modules/backends/smb/smb-backend";
-import { makeWebdavBackend } from "~/server/modules/backends/webdav/webdav-backend";
 import { configSchema, type IntegrationScenario } from "./runner/config";
 import {
 	formatError,
diff --git a/app/test/backend-integration/runner/config.ts b/app/test/backend-integration/runner/config.ts
index 60bd3556..ef2a0c5d 100644
--- a/app/test/backend-integration/runner/config.ts
+++ b/app/test/backend-integration/runner/config.ts
@@ -5,7 +5,7 @@ import {
 	repositoryConfigSchema,
 	type RepositoryConfig,
 } from "@zerobyte/core/restic";
-import { volumeConfigSchema, type BackendConfig } from "~/schemas/volumes";
+import { volumeConfigSchema, type BackendConfig } from "@zerobyte/contracts/volumes";
 
 const modeSchema = z
 	.union([z.number(), z.string().transform((value) => Number.parseInt(value, 8))])
diff --git a/apps/agent/src/volume-host/backends/smb.ts b/apps/agent/src/volume-host/backends/smb.ts
index 3d7ff5da..faf1018e 100644
--- a/apps/agent/src/volume-host/backends/smb.ts
+++ b/apps/agent/src/volume-host/backends/smb.ts
@@ -9,6 +9,19 @@ import { getMountForPath } from "../fs";
 import type { VolumeBackend } from "../types";
 import { assertMounted, executeMount, executeUnmount } from "./utils";
 
+const isUnsupportedAclMountOptionError = (message: string) =>
+	/invalid argument|unknown mount option|unrecognized mount option|bad option/i.test(message);
+
+const toSmbMountError = (error: unknown, usingContainerMapping: boolean) => {
+	const message = toMessage(error);
+
+	if (usingContainerMapping || !isUnsupportedAclMountOptionError(message)) {
+		return message;
+	}
+
+	return `${message} Your host/kernel may not support cifsacl, idsfromsid, or modefromsid. Enable "Map all files to container user/group" to fall back to the old uid/gid mapping behavior.`;
+};
+
 const checkHealth = async (mountPath: string) => {
 	const run = async () => {
 		await assertMounted(mountPath, (fstype) => fstype === "cifs");
@@ -79,8 +92,15 @@ const mount = async (config: BackendConfig, mountPath: string) => {
 
 	const run = async () => {
 		await fs.mkdir(mountPath, { recursive: true });
-		const { uid, gid } = os.userInfo();
-		const options = [`port=${config.port}`, `uid=${uid}`, `gid=${gid}`, "iocharset=utf8"];
+		const usingContainerMapping = config.mapToContainerUidGid ?? true;
+		const options = [`port=${config.port}`, "iocharset=utf8"];
+
+		if (usingContainerMapping) {
+			const { uid, gid } = os.userInfo();
+			options.push(`uid=${uid}`, `gid=${gid}`);
+		} else {
+			options.push("cifsacl", "idsfromsid", "modefromsid");
+		}
 
 		if (config.guest) {
 			options.push("username=guest", "password=");
@@ -102,8 +122,9 @@ const mount = async (config: BackendConfig, mountPath: string) => {
 		try {
 			await executeMount(args);
 		} catch (error) {
-			logger.error(`SMB mount failed: ${toMessage(error)}`);
-			throw error;
+			const message = toSmbMountError(error, usingContainerMapping);
+			logger.error(`SMB mount failed: ${message}`);
+			throw new Error(message);
 		}
 
 		logger.info(`SMB volume at ${mountPath} mounted successfully.`);
diff --git a/packages/contracts/src/volumes.ts b/packages/contracts/src/volumes.ts
index 1dd69660..669d8c77 100644
--- a/packages/contracts/src/volumes.ts
+++ b/packages/contracts/src/volumes.ts
@@ -31,6 +31,7 @@ export const smbConfigSchema = z.object({
 	username: z.string().optional(),
 	password: z.string().optional(),
 	guest: z.boolean().optional(),
+	mapToContainerUidGid: z.boolean().default(false),
 	vers: z.enum(["1.0", "2.0", "2.1", "3.0", "auto"]).default("auto"),
 	domain: z.string().optional(),
 	port: z