diff --git a/build/meta-bsp/classes/bsp.bbclass b/build/meta-bsp/classes/bsp.bbclass
index 678aa173f..83787bf9d 100644
--- a/build/meta-bsp/classes/bsp.bbclass
+++ b/build/meta-bsp/classes/bsp.bbclass
@@ -176,7 +176,13 @@ addtask do_deploy_boot_chain before do_deploy
 def __do_deploy_boot(d):
 
     if d.getVar('IB_STORAGE_MODE') not in ("remote", "http"):
-        bb.warn("Now mounting")
+        # Make deploy depend on an initialised storage. In "soft" mode this
+        # creates sdcard.img.<platform> on the fly when it is missing (the
+        # same work as scripts/init_storage.sh), so a fresh tree can deploy
+        # without a separate manual init step. deploy.sh already opened a
+        # sudo session, so the losetup/mkfs done here via `sudo -n` succeeds.
+        __do_fs_check(d)
+        bb.plain("Mounting storage")
         __do_fs_mount(d)
 
     __do_platform_deploy(d)
diff --git a/build/meta-filesystem/classes/fs_arm_common.bbclass b/build/meta-filesystem/classes/fs_arm_common.bbclass
index b82717add..03018982b 100644
--- a/build/meta-filesystem/classes/fs_arm_common.bbclass
+++ b/build/meta-filesystem/classes/fs_arm_common.bbclass
@@ -169,7 +169,13 @@ def __do_fs_mount(d):
             os.stat(img_path)
         except OSError as e:
             if e.errno == errno.ENOENT:
-                bb.fatal(f"{img_path} does not exist")
+                bb.fatal(
+                    f"Storage image '{img_path}' does not exist: the filesystem "
+                    f"for platform '{IB_PLATFORM}' has not been initialised yet.\n"
+                    f"Deploy normally creates it automatically; if you reach this, "
+                    f"initialise the storage explicitly by running:\n"
+                    f"    ./scripts/init_storage.sh\n"
+                    f"then run the deploy again.")
 
     p1 = os.path.join(WORKDIR, "p1")
     p2 = os.path.join(WORKDIR, "p2")