mssql 2012 backup use "mirror to" clause encounted error

i want to keep my db backup files on another server,and i got there have "mirror to" clause ,but when i use it ,it doesn't work well.

DECLARE @backupdate nvarchar(50)
DECLARE @BKFiledir nvarchar(100)
DECLARE @BKFiledir2 nvarchar(100)
DECLARE @dbname nvarchar(100)
declare @dbnameformat nvarc(100)
DECLARE @BKFilename1 nvarchar(100)
DECLARE @BKFilename2 nvarchar(100)
DECLARE @fulldir nvarchar(100)
DECLARE @fulldir2 nvarchar(100)
DECLARE @tagname nvarchar(100)
begin
DECLARE mycursor CURSOR FAST_FORWARD FOR
	 SELECT NAME FROM sys.databases where STATE_DESC='ONLINE' AND name in('SharePoint_AdminContent_cf5a6a6a-ac7a-4633-90c7-76f998b57cce');
OPEN mycursor;
FETCH NEXT FROM mycursor INTO @dbname;
WHILE @@fetch_status = 0
BEGIN
SET @backupdate =(
                select replace(
                       replace(
                       replace(convert(varchar(19), getdate(), 126),
                       '-',''),
                       'T',''),
                       ':','')
                )
set @BKFiledir=N'\\serverA\shareA\'
set @BKFiledir2=N'\\serverB\shareB\'
set @BKFilename1=@backupdate+'local.bak';
set @BKFilename2=@backupdate+'remote.bak';
if len(@dbname)>40
set @dbnameformat=left(@dbname,40)
else
set @dbnameformat=@dbname
set @fulldir=@BKFiledir+@dbnameformat+@BKFilename1
set @fulldir2=@BKFiledir2+@dbnameformat+@BKFilename2
set @tagname=@dbname+'-full Database Backup'

backup database @dbname
to disk=@fulldir
mirror to disk= @fulldir2 WITH  format,  NAME = @tagname, SKIP, NOREWIND, NOUNLOAD,COMPRESSION,  STATS = 10

FETCH NEXT FROM mycursor INTO @dbname;
end
close mycursor;
deallocate mycursor;
end
when i run the code on my production server,error occured:
Msg 3212, Level 16, State 0, Line 39
The mirror device "\\w01sql03db\share\SharePoint_AdminContent_cf5a6a6a-ac7a-4620160202140739local.bak" and the mirror device "\\w01sql2001\share\SharePoint_AdminContent_cf5a6a6a-ac7a-4620160202140739remote.bak" have different device specifications.
Msg 3013, Level 16, State 1, Line 39
BACKUP DATABASE is terminating abnormally.
but the oddest is the code can run successfully on my testing server,thank you everyone in advance.