On Mon, Mar 01, 2021 at 04:12:03PM +0100, Sedat Dilek wrote: > > OK, I see. > So I misunderstood the -o option. It was clearly documented in the man page: -o output_file Write the list of bad blocks to the specified file. Without this option, badblocks displays the list on its standard output. The format of this file is suitable for use by the -l option in e2fsck(8) or mke2fs(8). I will say that for modern disks, the usefulness of badblocks has decreased significantly over time. That's because for modern-sized disks, it can often take more than 24 hours to do a full read on the entire disk surface --- and the factory testing done by HDD manufacturers is far more comprehensive. In addition, SMART (see the smartctl package) is a much more reliable and efficient way of judging disk health. The badblocks program was written over two decades ago, before the days of SATA, and even IDE disks, when disk controlls and HDD's were far more primitive. These days, modern HDD and SSD will do their own bad block redirection from a built-in bad block sparing pool, and the usefulness of using badblocks has been significantly decreased. Regards, - Ted