ddrescue：第一次运行后重试失败的块

我用备份了故障的硬盘ddrescue。我使用的命令是

# ddrescue -vv -d -J /dev/sda /mnt/rescue/winxp.img winxp.map

该程序完成了大约60个错误。我只想重试失败的块。我在手册页中找到了此部分：

-m file
--domain-mapfile=file
    Restrict the rescue domain to the blocks marked as finished in the
    mapfile file. This is useful for merging partially recovered images of 
    backups, or if the destination drive fails during the rescue. Use '-' 
    as file to read the domain mapfile from standard input. Specialized 
    tools like ddrutility or partclone can produce a domain mapfile 
    listing all the used blocks in a partition, making the rescue more
    efficient.
-M
--retrim
    Mark all failed blocks inside the rescue domain as non-trimmed before
    beginning the rescue. The effect is similar to '--retry-passes=1', but
    the bad sectors are tried in a different order, making perhaps
    possible to rescue some of them.

我发出的下一个命令是

# ddrescue -vv -d -M -m winxp.map /dev/sda /mnt/rescue/winxp.img winxp.2.map

我认为这只会重试以前失败的块。但是，它似乎又从整个过程开始，并试图抢救整个磁盘。

有没有办法只重试失败的块，并在成功后将它们保存在先前的映像中？