Index: src/shell.c.in
==================================================================
--- src/shell.c.in
+++ src/shell.c.in
@@ -3321,10 +3321,11 @@
 #endif
 #ifndef SQLITE_OMIT_AUTHORIZATION
   ".auth ON|OFF           Show authorizer callbacks\n"
 #endif
   ".backup ?DB? FILE      Backup DB (default \"main\") to FILE\n"
+  "                         Add \"--append\" to open using appendvfs.\n"
   ".bail on|off           Stop after hitting an error.  Default OFF\n"
   ".binary on|off         Turn binary output on or off.  Default OFF\n"
   ".cd DIRECTORY          Change the working directory to DIRECTORY\n"
   ".changes on|off        Show number of rows changed by SQL\n"
   ".check GLOB            Fail if output since .testcase does not match\n"
@@ -5618,15 +5619,18 @@
     const char *zDestFile = 0;
     const char *zDb = 0;
     sqlite3 *pDest;
     sqlite3_backup *pBackup;
     int j;
+    const char *zVfs = 0;
     for(j=1; j<nArg; j++){
       const char *z = azArg[j];
       if( z[0]=='-' ){
-        while( z[0]=='-' ) z++;
-        /* No options to process at this time */
+        if( z[1]=='-' ) z++;
+        if( strcmp(z, "-append")==0 ){
+          zVfs = "apndvfs";
+        }else
         {
           utf8_printf(stderr, "unknown option: %s\n", azArg[j]);
           return 1;
         }
       }else if( zDestFile==0 ){
@@ -5633,20 +5637,21 @@
         zDestFile = azArg[j];
       }else if( zDb==0 ){
         zDb = zDestFile;
         zDestFile = azArg[j];
       }else{
-        raw_printf(stderr, "too many arguments to .backup\n");
+        raw_printf(stderr, "Usage: .backup ?DB? ?--append? FILENAME\n");
         return 1;
       }
     }
     if( zDestFile==0 ){
       raw_printf(stderr, "missing FILENAME argument on .backup\n");
       return 1;
     }
     if( zDb==0 ) zDb = "main";
-    rc = sqlite3_open(zDestFile, &pDest);
+    rc = sqlite3_open_v2(zDestFile, &pDest, 
+                  SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE, zVfs);
     if( rc!=SQLITE_OK ){
       utf8_printf(stderr, "Error: cannot open \"%s\"\n", zDestFile);
       sqlite3_close(pDest);
       return 1;
     }

Index: test/shell1.test
==================================================================
--- test/shell1.test
+++ test/shell1.test
@@ -254,11 +254,11 @@
   catchcmd "test.db" ".backup FOO BAR"
 } {1 {Error: unknown database FOO}}
 do_test shell1-3.1.4 {
   # too many arguments
   catchcmd "test.db" ".backup FOO BAR BAD"
-} {1 {too many arguments to .backup}}
+} {1 {Usage: .backup ?DB? ?--append? FILENAME}}
 
 # .bail ON|OFF           Stop after hitting an error.  Default OFF
 do_test shell1-3.2.1 {
   catchcmd "test.db" ".bail"
 } {1 {Usage: .bail on|off}}