dd_rescue 1.40 改进记录：
The -p/--preserve option now also copies extended attributes (including ACLs) if there are any.
Many checks and test cases have been added to make check.
Half-empty blocks are now detected now in sparse detection.
If copying with an odd file offset, the odd-sized write will be done first so that further accesses should be better aligned, which should help with performance (and optionally sparse detection)
GNU ddrescue (dd rescue, dd_rescue)是一个磁盘数据恢复工具。
官方首页：http://www.gnu.org/software/ddrescue/ddrescue.html
免费下载：http://mirrors.ustc.edu.cn/gnu/ddrescue/
来自:开源中国社区
