I am trying to format an external drive, but getting the error /dev/sdb1 is apparently in use by the system; will not make a filesystem here! Based on the internet, I have to run cat ...
I had a USB drive mounted on /dev/sdb1 and I want to reformat from NTFS to ext3. I did umount -l which unmounted the disk. I deleted the old partition using cfdisk. I ran mkfs.ext3, but got the error: ...